Common Name: Parasol Mushroom – The umbrella analogy is applicable to all mushrooms that have a stem or stipe holding up a cap or pileus. Since the umbrella (from the Latin umbra meaning shade) is equally a protection against rain or sun, parasol (Latin parare to shield and sol, the sun) is equally apt. Parasol is applied only to this mushroom out of the thousands of possible candidates due to its exceptionally broad cap held aloft by a relatively narrow handle-like stem.

Scientific Name: Lepiota procera – The generic name is from the Greek lepos, meaning rind, husk, or scale in reference to the scurfy surface of the cap. Procerus is Latin for tall. It is equally known as Macrolepiota procera to reflect the breakup of the original Lepiota genus into many new genera according to genetic DNA-based associations.

Potpourri: The lepiotoid mushrooms occupy an uncertain niche between the agarics and the amanitas. The agarics are exemplified by the “supermarket” White Button Mushroom (Agaricus bisporus), a cultivar of the Meadow Mushroom (Agaricus campestris) originating in the caves of Paris in the seventeenth century. They are characterized by having brown spores, free gills, and a partial veil.  The amanitas are among the most notable of all mushrooms, including the deadly, pearly-white Destroying Angel (Amanita disporangia) and the iconic red, white-dotted Fly Agaric (Amanita muscaria). Amanitas also have free gills, a partial veil, but with white in lieu of brown spores and a full veil. Lepiotas have white spores, free gills, and a partial veil, combining the traits of Agarics and Amanitas. [1]

Partial and full veils, as the names imply, are thin membranes that protect (veil) the gilled spore-bearing surfaces of some mushrooms until just before spore release to minimize any damage that could accrue during their emergence from the subterranean domain of the fungal mycelium. The partial or inner veil of Lepiotas, Agarics, and Amanitas is attached from the edge of the cap to a ring or annulus on the stem. The full or universal veil of most Amanitas covers the entire mushroom (like an egg), leaving a bowl-shaped remnant called a volva at the base of the stem, and frequently “veil fragments” on the cap. Free gills means that the gills are not attached to the stem affixed to the underside of the cap. Gill attachment is one of the primary features used by mushroom keys to distinguish one species from another. Notched and decurrent (descending the stem) gill attachments are the two primary alternatives to free gills. Another mushroom key distinction is the presence of scales on the cap of many lepiotoid mushrooms, especially the larger, “parasol-like” species. These structures are outgrowths from the cap and are not fragments of a gill-enclosing veil. In general, if a patch on the cap of a mushroom is flattened and light-colored, it may be a fragment of the universal veil. If it is angular and darker, it is a scale.   

The Agaric – Lepiota Family (Agaricaceae) and the Amanita Family (Amanitaceae)  are both in the order Agaricales. The fact that the Amanita muscaria is also called Fly Agaric is indicative of the still unravelling origin story of gilled mushrooms. Carolinus Linnaeus established the current system of biological classification or taxonomy with the publication of Species Plantarum in 1753. Fungi were placed in Cryptogamia, “hidden life” in Latin, one of the twenty four classes of the Plant Kingdom. This designation was for those plants that had reproductive systems that had not yet been determined (and were therefore hidden), as spores not visible to the naked eye had yet to be rationalized as a means of sexual transmission. The four orders of Cryptogamia were ferns (Filices), bryophytes like mosses and liverworts (Musci), algae which included all lichens, and fungi. There were ten genera of fungi, including Boletus for all mushrooms with pores instead of gills, Phallus for stinkhorns, Clavaria for coral fungi, Lycoperdon for puffballs, and Agaricus for all gilled mushrooms. [2] The bareboned Linnaean system persisted for about a century, becoming the baseline for those inclined toward generalizations that were adequate for comprehending the basic organization of life, a group that has since become known as the “lumpers.” The “splitters” are their antithesis, carving out increasingly narrow speciation in search of the biological holy grail of monophylogeny, having a single common ancestor.    

The genus Lepiota was one of the first to be stricken from the ranks of Agarics. This occurred in the late nineteenth century, as spore color became one of the characteristics that served to further distinguish mushroom genera.  Thus the original lepiotoids were defined as all white-spored mushrooms that had free gills that were not in the fully veiled Amanita genus. By 1888, those mushrooms with radiating ridges on the cap that look like and are called pleats were placed in the new genus Leucocoprinus (leuco means white in Greek). Ten years later, the one green spored Lepiota was moved to the genus Chlorophyllum. In 1948, Lepiotas with a different mechanism for growth involving what are called clamp connections were moved to Leucoagaricus and the largest Lepiotas were moved to Macrolepiota (macro is Latin for big) in which L. procera is currently placed. The splitting continued as DNA became the final arbiter of species. The only mushrooms of the approximately 1,000 species of white spored mushrooms with free gills that do not have a universal veil (Amanita) that remain in the original Lepiota genus are smaller in size mostly with scales on the cap and banding on the stem. [3] But more recent phylogenic evaluations of the 22 extant genera have shown that “taxonomic circumscription and segregation of the genus Lepiota has been problematic.” [4] Which is why, for the sake of some consistency in field identifications, Parasol mushrooms as an archetype as used here should suffice. 

Since this article is about Parasol Mushrooms, it is apropos to address the mushroom umbella analogy. The logic of syllogism would suggest that if it looks like an umbella, then it must be a rain shield. In reality, the cap has the opposite function – to retain water. The umbrella shape is to ensure that there is enough humidity as water vapor on the underside of the cap for water droplets to condense in the vicinity of the spore-bearing gills. To explain why this is so, a few points about mushroom physiology must be noted. A mushroom is a fruiting body that is produced by a fungus, the tangled mass of thread-like strands called a mycelium that is wholly underground or inside dead wood. The only function of the fruiting body mushroom is to spread the reproductive spores into the environment to propagate the species (like apples on an apple tree). When a fungal mycelium is ready to reproduce, it forms a self-contained and out of sight proto mushroom called a primordium. Once fully formed, the fungus waits for promising weather, which is quite frequently after substantial rain has fallen. This is why mushrooms mysteriously appear overnight after rain; they are already there, ready, and waiting. Once the mushroom erupts from its hypogeal lair, the cap opens, separating the partial and/or universal veil if it has one, exposing the gills to the surrounding air for the first time. [5]

So why does the air under the mushroom cap need to have plenty of water vapor? Because the spores need to be literally shot away from the gills so that they can freefall into the wind for dispersal. The motive force that ejects each spore outward is the result of the condensation of water vapor into a tiny droplet. Gills are like vertical, side-by-side slats suspended from the underside of the cap. The reason for this arrangement is to maximize the surface area available to be able to produce as many spores as possible; a flat surface would provide only a small fraction of the area with gills.  Because the probability of any one spore successfully germinating to produce a new fungus is vanishingly small, mushrooms need to produce millions of spores to succeed. Since the gills are mounted vertically on the gills rather than horizontally, a spore, if simply released, would remain stuck to the surface. Nature’s evolutionary solution is to literally shoot the spore horizontally, away from the side of the gill into the air gap between gills so that it can then fall due to gravity. Each spore is held at the tip of a stalk called a sterigma at a point called the punctum lacryman (Latin for the “point that cries”) depicted in the figure at A. It is here that the water vapor condenses, shown in B. The water droplet extends onto the spore surface in C due to surface tension, causing the center of gravity of the spore/water mass to shift rapidly to create what is called a surface tension catapult force (marked with an F in the figure). The miniscule (about 10 microns in diameter) spore is ejected outward at a speed of about 10 miles per hour with an acceleration of 25,000 times the force of gravity (called G-force). First hypothesized at the beginning of the 20^th century, the catapult force was captured by high-speed camera about twenty years ago. The mechanics was demonstrated conclusively by modelling the spore/sterigma interface using polystyrene hemispheres just five years ago. [6] Fungi have been described as fantastic with good reason.

Parasol mushrooms are extolled as one of the commendable edible species, with commentary that ranges from “choice, with caution” [7] to “tender caps … edible and highly regarded by many mycophagists.” [8] An abundance of caution is warranted. There are a number of species that are quite similar in appearance to L. procera with edibility caveats that range from unknown and therefore not recommended to demonstrably poisonous. There is even one species sometimes known as the Deadly Lepiota (L. josserandii) since it has the same amatoxin chemicals that are found in the most notable of all deadly mushrooms, the Destroying Angel (Amanita bisporigera) and the Death Cap (A. phalloides). The simple fact that the Parasol-type mushrooms are similar in characteristics to the problematic Amanitas (white spores and partial veil) should raise the red flag potential for mistaken identification. Absent a complete and through assessment of a parasol-like mushroom by a competent expert to include spore color, veil attachments, and scale configuration, consumption is unwise. There is an old saying: There are bold mushroom hunters and old mushroom hunters, but no old, bold mushroom hunters. The other aphorism of note is that you can eat any mushroom – once. The alleged ubiquity of deadly mushrooms in Anglo-Saxon culture and literature is a matter of phobia and not fact. The North American Mycological Association (NAMA) has maintained a national mushroom poisoning data base since 1982. It is not comprehensive since it relies on proffered reports; there is no requirement for medical and veterinary establishments to report mushroom poisonings. However, it provides some baseline data that is instructive. There were a total of 1700 reports of mushroom poisoning reports over thirty years with the vast majority involving ingestions by young children and dogs. Almost all result in various degrees of temporary gastrointestinal distress and full recovery with no lingering long-term effects.  Contrary to the perception of the general public, only about 10 percent of poisonous mushrooms― i.e. those which cause nausea and diarrhea (and sometimes both) ― are potentially deadly. Deadly plant toxins like those of hellebore and white snakeroot are much more common than deadly fungal toxins.  There is one lepiotoid mushroom that deserves special attention. According to NAMA, “Of the mushrooms generally considered poisonous, the one far most often consumed is Chlorophyllum molybdites. It is large and meaty; it resembles a generally choice edible, it tastes good, and it grows in lawns and parks. Chlorophyllum molybdites quickly rewards the unwary with gastric distress, vomiting, and diarrhea lasting several hours.” [9]  

The Green-spored Lepiota (Chlorophyllum molybdites) is variously known as “the vomiter” and “the gut-wrencher” for its notable stomach and bowel emptying effects. [10] There are a number of characteristics that can be used to make the distinction between the edible lepiotoid mushrooms and its poisonous doppelgänger. Habitat, distribution, and season are the most notable. Green-spored Lepiotas appear in clusters in grassy areas in the heat of summer and their edible cousins are found singly in mulch and open woods in the fall. What about the spore color? While it is true that C. molybdites has dingy greenish colored spores when fully open and mature, the gills are white and only turn slightly dingy with age. The green, although unique among mushrooms, is more a nuance than the convincing traffic light color. Most edible fungi are better when collected young and fresh; just about everything (and everyone) gets tough and sinewy with age. This then is the bane of the mushroom hunter. For Green-spored Lepiotas gathered while still immature, the gills would be white with scarcely a hint of the tell-tale green. The scenario: A flush of succulent looking white mushroom just like the one that you buy at the store pop up in the courtyard of your apartment complex and you rush out to gather, cook, and eat them. A beautiful summer day turns into a medical emergency in a matter of hours. [11]

References: 

1. Arora, D. Mushrooms Demystified, 2^nd edition, Ten Speed Press, Berkeley, California, 1986, pp 293-310.

2. Linnaeus C.  Species Plantarum. Stockholm, Sweden,1753 : pp 1061-1186.

3. Vellinga, E. “An Overlooked California Lepiota- Old or New?” Fungi Magazine, Volume 2 Number 4, Fall, 2009, pp 7-9.

4. Johnson, J. and Vilgalys J. “Phylogenetic systematics of Lepiota sensu lato based on nuclear large subunit rDNA evidence”. Mycologia. 10 June 1998 Volume 90 Number 6,  pp 971–979.

5. Kendrick, B. The Fifth Kingdom, Focus Publishing, Newburyport, Massachusetts, 2000, pp 80-98. This is the single best desk reference for the Kingdom Fungi.

6. Chang, K. “Fungi Physics: How Those Spores Launch Just Right” New York Times, 27 July 2017. https://uphyl.pratt.duke.edu/NYTimes_Fungi_2017.pdf    

7. Lincoff, G. The National Audubon Society Field Guide to North American Mushrooms, Alfred A. Knopf, New York, 1981, p 520.

8. Roody, W. Mushrooms of West Virginia and the Central Appalachians, The University Press of Kentucky, Lexington, Kentucky, 2003, p 72-73

9. Beug, M. “An overview of Mushroom Poisonings in North America”. Mycophile Volume 45 Number 2, March/April 2004.

10. Salzman, J. “ Your Yard Might Be Home to the “Vomiter” Mushroom” Huffington Post 29 April 2011.

11. Hedgpeth, D. “Virginia family hospitalized after eating wild mushrooms found at apartment complex” Washington Post, 22 August 2018.

Common Name: Woolly Bear Caterpillar, Woolly Worm, Fuzzy Bear, Hedgehog Caterpillar – The dense tufted bristles are black at both ends and brown in the middle with a texture that is  similar to wool. The short, rounded and blunt shape suggests an ursine association ― ergo, woolly bear. The caterpillar is the larval stage of the Isabella moth.

Scientific Name:  Pyrrharctia isabella – Pyyrh is the Greek word meaning red or tawny. Arctia is derived from the Greek word arktos, which means bear. The Isabella moth has red markings on the wings and is a northern species ranging into the arctic regions. The association of bear with arctic is due to the astronomical importance of Ursa Major, the Great Bear also known as the Big Dipper. The pole star Polaris at one end of Ursa Minor and  pointed to by two of Ursa Major’s stars is used in celestial navigation to locate true north. Isabella is a color that ranges from yellowish brown to olive brown, the basic wing color. Former scientific name Isia isabella.

Potpourri: Caterpillars are the larval stage of insects of the order Lepidoptera comprised of butterflies and moths. The distinction between these two groupings is as arbitrary as the common names given to animals and plants that are mostly descriptive with occasional mythic etymologies. Butterfly, as a case in point, is thought to derive from the belief that witches in the shape of flying insects stole milk and butter. Butterflies are most notable for their  brightly colored wings and zigzagging drunkenly across meadows in daylight. Moths are everything else that flies like a butterfly (and doesn’t sting like a bee). They are united in one order due to the physiology for which they are named, as butterflies and moths all have scaly (lepis in Greek) wings (pteron in Greek). The other almost universal difference is that butterflies are diurnal and moths are nocturnal. Their larvae, for the most part, stay hidden in the foliage as a survival matter. The trundling woolly bears are an exception to this rule. [1]

The woolly bear caterpillar is best known for its headlong scramble across trails in late fall and early spring. They have been observed by wayfarers since the colonial era, gaining a measure of notoriety. The reason for their haste at the larval sprint pace of four feet per minute is unknown, but there is a continuity of direction that suggests a specific goal. Conjecture is based in part on the well-established fact that woolly bears overwinter as caterpillars, freezing nearly solid as temperatures plummet according to season, latitude, and elevation. In the fall months, this would imply that there was some necessary location favoring cryogenic hibernation. However, since shelter from cold cannot be a factor, seclusion could only be to prevent predation ― but any nook or cranny would do. In the spring, the path is reversed for pupation, also a matter of finding an out of the way place to wait in helpless suspended metamorphic animation. Regardless of the destination, physiological actions occur in preparation for migration. A peak in the level of ecdysteriods (hormones that promote molting) triggers a cessation of feeding and gut evacuation followed by the quixotic quest. Since they are and have been a successful species, relocation has promoted propagation. This is in spite of the fact that caterpillars squashed while crossing busy roads and trails cannot equally promote longevity. The evolved ability to endure winters as larvae is certainly a relevant factor. [2]

Woolly bear is a contradiction on two counts: Caterpillars are not bears and their “wool” is not a winter coat. The stiff hairs called setae that extend outward in all directions from the larval body are the most notable features of the caterpillar, blocking out all other detail. The function of the hair is to some extent protective, as it blocks wasps like yellow jackets from direct access to administer their all too lethal sting. [3] Woolly bears instinctively roll up into a protective ball of spines to augment this defensive measure when frightened; this is the origin of the alternative common name hedgehog caterpillar. The dense hair also allows for controlled whole-body freezing, a rather surprising capability that is shared by only a few other animals, notably wood frogs.

As cold temperatures set in, a natural antifreeze compound composed of lipids and alcohols called glycerol is produced and distributed to the body by hemolymph, the blood-like body fluid of insects. The change in cryoprotectants with temperature has been verified in laboratory conditions. [4] As the cold slowly seeps in, the entire body except the very centers of the cells freeze solid in anticipation of the spring thaw. This capability has extended the range of woolly (polar) bears to the Arctic, where they have survived winters with temperatures as low as 90 degrees F below zero. Their life sequence is slowed to match the metabolic reduction to the extent that the normal one-month metamorphosis from larva to adult moth can take up to 14 years. [5] 

The distinctive black-brown-black banding of the setae of the Isabela moth larva is the basis for the mythology of woolly worm weather prediction. It is not altogether unreasonable to believe that animals might be able to sense the mood swings of climate. The traditional folk wisdom of caterpillar color bands for winter forecasting may have been a direct assimilation of Native American lore. In any agrarian society, crop cycles are crucial to survival. Intelligence about the beginning, duration, or end of winter would be of abiding interest. For example, the counterpoint to woolly bears and the harshness of winter is the groundhog’s shadow that allegedly determines its duration. In its most general form, the definitive metric of woolly bear winter is the width of the middle brown band between the two black end bands. A narrow brown band is indicative of a severe winter whereas a broad brown band indicates a mild weather.

The quaint custom gained national credence in 1948 when two entomologists from the American Museum of Natural History in New York City collected 15 woolly bears and predicted a mild winter based on band width averages. Rather than publish a scientific paper, the two insect experts provided their results to a reporter whose article made the front page of the New York Herald Tribune, a respected newspaper. When their prediction proved correct, woolly bear wisdom gained a national audience. For the next seven years, the paper’s readers demanded annual weather predictions. The custom eventually fell out of fashion as its randomness inevitably became obvious. [6]

There is no correlation between woolly bear coloring and winter.  The relative size of the brown center band relative to the two black end bands is a matter of nutrition and age.  The more fruitful the summer feeding season, the larger the caterpillar will become, its growth narrowing of the central brown section. The age factor involves molting. Woolly bears grow and mature in six intermediate steps called instars, shedding their skin each time and becoming less black and more brownish sequentially. It might be feasible to correlate the bounty of a summer season with woolly bear ring sizes, but that is after the summer fact and has nothing to do with the winter future. The established biology of caterpillar growth and molting has had little effect on the public embrace of the original myth, even adding new variants. For example, the woollier the coat, the worse the winter. A more creative version concerns the direction of transit. A woolly bear moving south is escaping the coming harsh winter and vice versa, going north if milder.

In an attempt to coopt the success of Punxsutawney Phil, several small towns have inaugurated fall celebrations featuring nature’s herald as star attraction. The most well known is the Woolly Worm Festival held annually in October to promote tourism to the small town of Banner Elk, North Carolina. The event is promoted as a race between contestant caterpillars in heats to determine the champion woolly worm. The festival has drawn as many as 20,000 attendees witnessing racing heats involving 1,000 participant larvae. The winner is the official  weather prophet, the color of each of its 13 segments correlated to the 13 weeks of winter. Black indicates below average temperature, light brown above average temperature, dark brown average temperature, and something called fleck is low temperature with light snow. This not without financial remuneration as incentive. The winning worm receives a $1,000 prize. [7]

The adult moth to which the woolly bear larva pupates is one of the tiger moths of the family Arctiidae that are mostly moths in butterfly clothing … many are brightly colored with spots and stripes in contrast to the whites, browns, and grays of the majority of moths. The Isabella moth is an outlier with muted yellow-brown wings as its name implies. Tiger moths in general are also capable of producing audible sounds, a trait not normally associated with moths, mostly seen but not heard. Noisemaking is to deter bats, the nemeses of “mothdom” in their shared nocturnal air space. Bats are small-bodied and warm-blooded, consummately voracious to maintain the necessary energy input. Tiger moths, and the closely related owlet moths (Family Noctuidae – the ones most frequently seen fluttering around lights at night as their nocturnal name implies; their larvae are cutworms) have large eardrum-like structures called tympanic organs to detect the echolocation sounds made by bats. Located on either side of the head with a sensor for intensity that correlates to distance, tiger and owlet moths can determine the direction and the distance of an approaching bat and take appropriate evasive action. The tiger moths take the listening and evading strategy a step further, emitting a clicking noise that is thought to disrupt bat sonar altogether. [8] Evolution is powered by predators.

Bright colors are counterintuitive for defenseless insects that would likely have better survival chances by being neither seen nor heard. This is as true for the larval, caterpillar stage as it is for the adult moth stage. The black brown banding of woolly bears is eye-catching, particularly when it is moving across open areas. Tiger moths, at all life stages, widely employ distastefulness as a defensive mechanism. The use of vivid colors by animals to indicate that they are not palatable is called aposematism. Predators learn to avoid them after the first encounter, recognizing the color and pattern that is intentionally obvious for that reason. Monarch butterflies and red efts are good examples.

It has been established in laboratory testing that woolly bear caterpillars consume plants containing pyrrolizidine alkaloids for chemical resistance to lethal parasitic tachinid flies. In fact, experiments showed that they do this as a matter of self-medication, one of the first instances of some form of cause and effect invertebrate cognition. [9] Pyrrolizidine alkaloids found in some asters and legumes are one of the most toxic substances to both domestic animals and humans, causing severe metabolic disruption. Wild animals learn to scrupulously avoid them. Woolly bear caterpillars, along with many other tiger moth caterpillars that live exposed lives, are able to  live rashly and openly only because they are chemically protected. Tiger moth larvae are also among the most polyphagous of all the lepidopterans, eating as many as 88 different plant species. [10] It is probable that the chemistry of the foods they eat is inclusive of pyrrolizidine alkaloids.  

It may be concluded that woolly bears are exceptional caterpillars. Taking survival of the fittest seriously, they have evolved a formidable suite of adaptations. Extending poleward to the frozen northern latitudes to escape bug and bird infested trailways, they eschew the warmth of woolens for woolly-ness. Seeking nutrition across a broad range of foliage choice, they ensure that there will always be a dessert of protective poisons. But why the annual diaspora? Maybe they are the tramps of the lepidopterans with Bruce Springsteen’s mandate … they are born to run. But they don’t predict the weather.

References:

1. Milne, L. and Milne, M. National Audubon Society Field Guide to North American Insects and Spiders, Alfred A. Knopf, New York, 1980, pp 697-698, 790.

2. Wagner, D. “The Immature Stages: Structure, Function, Behavior, and Ecology”. In Conner, William E. (ed.). Tiger Moths and Woolly Bears: Behavior, Ecology, and Evolution of the Arctiidae. 2009 Oxford University Press  pp. 31–53.

3. Rich, G. “How woolly bear uses clever tricks to survive” Washington Post, 23 November 2021.

4. Layne, J. and Kuharsky, D..  Triggering of cryoprotectant synthesis in the woolly bear caterpillar (Pyrrharctia isabella Lepidoptera: Arctiidae)”. Journal of Experimental Zoology. 1 March 2000 Volume 286 Number 4 pp 367–371.

5. https://www.weather.gov/arx/woollybear – The U. S. Weather Service website.

6. https://bygl.osu.edu/index.php/node/1713              

7. http://www.woollyworm.com/     

8. Marshall, S. Insects, Their Natural History and Diversity, Firefly Books Ltd., Buffalo, New York, 2006, pp 174-177, 212-213.

9. Singer, M. et al “Self-Medication as Adaptive Plasticity: Increased Ingestion of Plant Toxins by Parasitized Caterpillars”. PLOS ONE. 10 March 2009 Volume 4 Number 3.

10. Wagner, op cit.

Common Name: Yarrow, Woundwort, Milfoil, Staunch weed, Thousand-leaf, Old Man’s Pepper, Bloodwort, Devil’s nettle – Yarrow is the English variant of the Anglo-Saxon word gearwe originally from Old High German garwa. There are many colloquial names in different languages and localities. The German schafgarbe, French herbe à dinde, Swedish rölleka, and Italian achillea are all yarrow by another name.

Scientific Name: Achillea millefolium – The name of Achilles, the Greek hero of Homer’s Iliad, is recognizable as the genus. The species name means “thousand-leaf” in Latin ―  one of the common names. The distinctive appearance is characterized by small fern-like leaves extending outward from the upright stem holding up a white bouquet.

Potpourri: Yarrow is one of the most common and well-known medicinal herbs in the world. With a circumboreal reach, it encompasses the temperate regions of the northern hemisphere spanning both Eurasia and North America across a broad swath of latitudes. It grows in open areas in copious clusters marking its location with flat topped clusters of white flowers, one of three species in the mid-Atlantic region with similar appearance. The other two are white snakeroot, the poisonous weed that killed Abraham Lincoln’s mother and Queen Anne’s lace, the wild carrot, both of which are in the Aster family. Yarrow is a composite flower of the Daisy family, the flower-like “head” consisting of many small flowers. Familiarity and ease of identification favored experimentation by native peoples globally, using it in the treatment of a variety of medical conditions that vary according to tribe and custom.[1] Both Native Americans and the Europeans who ventured westward across the Atlantic independently exploited yarrow’s unusual chemistry according to their widely divergent traditions. Yarrow is one of the few (and possibly the only) plants with that distinction. Other herbals used in the colonial era were either imported from Europe like heal-all or adapted from local Indian usage like black cohosh.

The ancestry of yarrow extends to the origins of Western civilization. Achillea is an eponym for Achilles, the main Greek protagonist in Homer’s Iliad that chronicles the Trojan War. He was killed with an arrow that struck him in the heel left unprotected when he was dipped into the magical river Styx ― Achilles’ heel a consequent metaphor for anything vulnerable. Greek mythology attributes the education of Achilles to the centaur Chiron, an expert in herbal medicine where he learned of the healing powers of yarrow.  Used to staunch the wounds of fallen Greek warriors at Troy, yarrow thereafter became known as herba militaris, Latin for military medicine and retained in the common name woundwort. While the Homeric tale is certainly apocryphal, knowledge of the healing properties of yarrow was well established from the earliest days throughout Europe. This is evident from its continued use as traditional medicine in many countries. [2] Achillea was the obvious choice for the genus when Linnaean taxonomy was first established in the eighteenth century.

The extent to which yarrow is accepted in Europe as an effective medicinal herb is evidenced by the publication of an assessment report by the European Medicines Agency in 2020. Citing the “whole or cut, dried flowering tops” as the most effective part of the plant, the prescription  is for a minimum of 2 milliliters per kilogram of “essential oils.”  Based in part on the inclusion of  Achillea millefolium in the Pharmacopoeias (approved drug lists) of Great Britain, France, Hungary, Austria, Romania, and the Czech Republic and also in the German Commission E Monograph, the assessment report lists its accepted medical uses in the various jurisdictions. Not surprisingly, the original Achillean wound use is the most prevalent. Topical application of the essential oil staunches bleeding from the nose or anywhere else, improves wound healing, and reduces skin inflammation. Taken internally, the most common treatment is for gastrointestinal difficulties such as loss of appetite and upset stomach. However, it is also used to treat colds in Great Britain, “cramp-like conditions of psychosomatic origin” in Germany, and spasmodic colitis in France. [3] It is likely that Europeans also had many other local customary uses with their own local historical traditions which gradually coalesced into those few found more effective and reliable across the continent as cities and commerce expanded. One example is its use as snuff from which the name Old Man’s Pepper derives.

On the other side of the North Atlantic, Native Americans employed yarrow more extensively. Applications ranged from specific symptoms to panacea. Cherokee of the Southeast used yarrow mostly for hemorrhages both internally and externally, taking advantage of its astringency. They also smoked the leaves to treat catarrh, a condition resulting from excessive mucous production. Further west the Blackfoot Indians of the Great Lakes region used it as a cure-all, rubbing whatever body part was affected by sickness.  In one of the few documented veterinary applications, they also made an eyewash for their horses. On the Great Plains, the Cheyenne used an infusion of dried leaves and flowers to treat just about anything, including chest pains, nausea, cold, coughs, fevers, and respiratory diseases. [4] There are many other references to the use of yarrow by Native Americans. According to the USDA database “Native Americans used tea made from common yarrow to relieve ear-, tooth-, and headaches; as an eyewash; to reduce swelling; and as a tonic or stimulant.” [5] Since there was minimal intertribal coordination and communication with a fair amount of rivalry and some conflict, there were few opportunities for tribal healers to learn of and employ common remedies for similar ailments.

There is a good reason for the diverse and sometimes contradictory uses of yarrow. It has a complex chemistry with more than 100 biologically active chemicals. [6] According to the European yarrow report, it contains “3-4% condensed and hydrolysable tannins; 0.3-1.4% volatile oils, mostly linalool, borneol, camphor, β-caryophyllene, 1,8-cineole, and sesquiterpene lactones composed of guaianolides, mainly achillicin … and flavonoids (apigenin, luteolin, isorhamnetin, rutin).” This is in addition to an impressive array of amino acids,  fatty acids, vitamins,  alkaloids, bases,  alkanes, saponins,  sterols, sugars, and at least one poison (thujone). Knowing yarrow chemistry is one thing. Knowing what the chemical compounds do is quite another. Limited research attributes the salubrious effects of yarrow to the essential, volatile oils and sesquiterpene lactones. However, every one of the constituents is naturally produced by yarrow for some reason and that must in some cases be to deter browsing animals and sucking insects. The ASPCA lists yarrow as toxic to dogs, cats, and horses, causing vomiting, diarrhea, and dermatitis. [7]  Some birds use yarrow to build their nests, which has been shown to reduce the number of fleas by fifty percent. [8] Conversely, the USDA estimates that 20 percent of cattle and horses and 40 percent of sheep and goats graze on yarrow with no ill effects and evident nutrition.

The contradictory effects of advertent yarrow consumption by humans and domesticated animals can be attributed to chemical differences according to geography, habitat, and hybridization. Many plants form hybrids due to variations in the numbers of chromosomes. Most living things are diploid, having two sets of chromosomes excepting the sex cells that are haploid (23 chromosomes in humans) that join to form the diploid gamete. Having more than two sets is called polyploidy.  Yarrow is in something of a class by itself, with diploid, tetraploid, pentaploid, hexaploid, septaploid, and octoploid variants.[9] Since there is no commercial motivation to fund a detailed study of yarrow’s variability according to genetics (it is a weed after all) there is little scientific data. One of the few studies consisted of testing up to forty yarrow plants from each of sixty six sites to correlate polyploidy with chemistry. Hexaploid yarrows found in dry and nutrient-poor habitats had low levels of achillicin, one of the sesquiterpene lactones. Tetraploid yarrows had high levels of achillicin that correlated to the presence of phosphate, magnesium, and manganese in the soil. Noting that “the concentration varies widely in a population of a species,” the study concluded that “This makes the use of herbal medicine difficult.” [10] It is reasonable to conclude that the diverse and contradictory effects of consuming yarrow as either food or medicine is due to local variations in the quantity and quality of the many chemical compounds.

The fact that yarrow from one field may be different from yarrow in another field has not stopped the herbalists from extolling its virtues indiscriminately. In one herbal characterized as a Gaia original (The Greek personification of Earth), yarrow is noted for its “actions” that include “diaphoretic, febrifuge, peripheral vasodilator, hypotensive, antithrombotic, vulnerary, styptic, emmenagogue, anti-inflammatory, astringent, diuretic, digestive, and antiseptic.” That seems to cover about everything except cancer and athlete’s foot. A “hot infusion” of yarrow lowers fever by causing sweating to eliminate toxins and lowers blood pressure while simultaneously getting rid of  blood clots. Good for the stomach to improve digestion while getting rid of ulcers, yarrow also works on arthritis and rheumatism. In the “stops bleeding” category, reducing excessive menstruation and treating bleeding piles are included. [11] And this is one of the more rational prescriptions, based at least in part on traditional use of some type of yarrow somewhere. For those who adhere to the 17^th century Doctrine of Signatures as a basis for establishing medicinal purpose, one gets “the umbel-like umbrella of yarrow betrays its properties to reinforce the protective auric shield.” What this golden (Au is the symbol for the element gold, aurum in Latin) shield is supposed to do is not clear, but a further explanation provides “lacy leaves and umbel flowers represent aeration of the lungs and blood stream.” [12] I wonder why?

Those who favor herbal remedies over pills and potions dispensed by the pharmaceutical industry believe they are on moral high ground. It is certainly true that the only drugs were herbs up until the dawn of the 20^th century. There was no aspirin for headache and no erythromycin for strep throat. The apothecary shop contained dried herbs and tinctures of various mixtures … but there were also ingredients like bat wings and tiger pee. Some of the traditional herbal remedies actually worked and have since taken their place on the drug store shelf. Some natural substances like opium, have been synthesized; heroin was originally marketed as a pain reliever until addiction emerged as a serious problem. The subsequent opioid epidemic has forever tainted the reputation of big pharma.  However, absent a scientific trial with an untreated control group to use as a baseline for measuring different outcomes, there can be no confirmation of the benefits of any herbal product beyond anecdote. Trials are expensive and drug companies are only willing (and able) to foot the bill if subsequent profits on sales can pay for the research and development. The placebo effect and different reactions to the same drug by different individuals all add to the confusion. The bottom line is that herbal supplements taken for general health and well being are generally benign, and, if you believe they work, they probably do. However, most people who are really sick go see a doctor who prescribes medications from the pharmacy and not the woods. This would include yarrow, in spite of its historical herbal heritage.

References: 

1. Niering, W. and Olmstead, N National Audubon Society Field Guide to North American Wildflowers, Alfred A Knopf, New York, 1998, pp 354-355.

2. https://www.botanical.com/botanical/mgmh/y/yarrow02.html      

3. Assessment report on Achillea millefolium L., herba European Medicines Agency, 23 September 2020. https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-achillea-millefolium-l-herba-revision-1_en.pdf    

4.  Ethnobotany database for Native American plant medicinal usage. http://naeb.brit.org/uses/search/?string=Achillea+millefolium+   

5. https://www.fs.fed.us/database/feis/plants/forb/achmil/all.html  

6. Foster, S. and Duke, J. Eastern Central Medicinal Plants and Herbs, Houghton Mifflin, Boston, 2000, p 74.        

7.  https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/yarrow    

8. Shutler D, Campbell A. “Experimental addition of greenery reduces flea loads in nests of a non-greenery using species, the tree swallow Tachycineta bicolor“. Journal of Avian Biology. 8 September 2007 Volume 38 Number 1 pp 7–12.  

9. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200023010   

10. Michler, B.  and Arnold, C. . “Predicting Presence of Proazulenes in the Achillea millefolium Group”. Folia Geobotanica. 1999  Volume 34 Number 1 pp 143–161.

11. McIntyre, A. Herbs for Common Ailments, Simon and Shuster, New York, 1992, p 60.

12. Graves, J. The Language of Plants, Lindisfarne Books, Great Barrington, Massachusetts, 2012, p 122.

Common Name: Bald Eagle, American eagle – The white head feathers convey baldness in contrast to the darker body plumage. Eagle is anglicized from the Latin Aquila.

Scientific Name: Haliaeetus leucocephalus – The generic name is from the Greek hali meaning ‘sea’ and aietos, meaning ‘eagle’ to characterize the riparian habitat of the fish-eating bald eagle. The species name means ‘white head’ in Greek. A white-headed sea-eagle is the intended description.

Potpourri: The resurgence of the bald eagle population from a low of about 500 nesting pairs in the contiguous United States in the second half of the twentieth century to ten times that many today is a promising harbinger for reining in the excesses of our own overpopulation. The seemingly inexorable slide toward extinction of the empyreal symbol of the American experiment was a metaphor for the end of the freedoms that the New World once offered; its restitution offers hope. There is perhaps nothing more inspiring to those who seek nature on the trails than to be able to appreciate the majesty of the bald eagle, as much a preeminent symbol for Native Americans as it is to those of us who later immigrated. As the only eagle that is unique to North America, it is entirely fitting that it was chosen as the symbol for what the newly independent Americans aspired to be: strong and free. The bald eagles have returned to the rivers and lakes of their original, native, home – like a phoenix rising from the ashes. [1]

Accipiters (Latin for hawk) are generally considered to be birds of prey and synonymous with the more loosely defined term raptors. They are assigned to their tree-of-life positions due to their characteristic hooked beaks, curved and grasping talons, and keen vision (eagle-eyed). They include both the bald and golden eagles in addition to hawks, kites and the osprey. The sea eagles are distinguished in a separate genus Haliaeetus (from the Greek hali meaning ‘sea’ and aietos, meaning ‘eagle’) in the family Accipitridae due to their preference for fish as a dietary staple; their habitat along streams and the shores of lakes is a consequence. The closest relative of the bald eagle is the Eurasian white-tailed eagle (H. albicilia); the two parted ways about 15 million years ago as the Atlantic Ocean broadened the separation of the North American from the Eurasian plate. An international team of over 200 researchers recently completed a revision to the avian family tree based on the full genomes of 48 species. In addition to the finding that the ancestor of all birds (the so-called teeth-to-beak transition) lived about 116 million years ago, the study found that the closest relatives to the eagles are the new world vultures. [2] The new world (turkey and black) vultures and the California condor are also sometimes considered raptors even though they eat carrion.   Perhaps this better explains why the bald eagle eats carrion like the vultures and also hunts live prey like the hawks and kites; its refection mostly fish (56 %) but sometimes rodents (14%) and other birds (28%). [3]

The carrion-eating behavior of the bald eagle is typically considered pejorative, a blot on America’s escutcheon. However, it should be noted that the bald eagle is a very large raptor, second only to the California condor in size; it is accordingly at the top of the food chain with no predators other than humans. The consequence of having a large body of about 12 pounds (including 1 pound of feathers and a half pound of bone) is the need to consume a substantial quantity of food and necessitates a wingspan of about 6 feet to provide the needed aerodynamic lift to get its large bulk off the ground. The maneuverability of a drone-sized raptor operating within the physically confining restraints of the eastern forests is limited to mostly open areas, arboreal habitats are only suited for roosts. While the bald eagle can reach speeds of 40 miles per hour in open air and almost 100 miles per hour in a dive, this does not necessarily help in the successful prosecution of predation. However, the Gadarene plunge of a bald eagle directed at any other predator that has successfully concluded a hunt is almost guaranteed to chase it away from its prey. This is undoubtedly a matter of evolutionary survival and logic; why bother to expend all that energy in the likely fruitless enterprise of chasing rabbits when the same result can be achieved vicariously? Rather than condemn the bald eagle for the “cowardly” behavior of carrion eating, we should laud it for its intelligent choice. It is also worth noting that, with the exception of hunters, fishers and some small livestock farmers, all humans who are not vegetarians are also carrion eaters.

The family life of the bald eagle is equally worthy of human emulation and is of particular appeal to those who trend to the conservative side of social perspectives: they are monogamous and normally have two eaglets nurtured to viability in a home that is built to last. Once an eaglet reaches sexual maturity at about five years of age, it advertises its puberty with a change of plumage. Immature eagles have mottled feathers that cover the entire body and head uniformly until molting triggered by hormonal factors engenders the contrasting white-feathered crown and nape of the pubescent adult. With eyes almost as large as a human’s but with vision four times more acute (that would be 20:5), the location of a mate is facilitated by the chiaroscuro effect of the white head in contrast to black body. Mate selection is permanent for the approximate 20 years remaining should both attain average eagle longevity. [4] The couple’s honeymoon enterprise is to build a nest at or near the top of a tall tree that is in close proximity to open water. As a permanent home, the nest is embellished and expanded on a yearly basis to the extent that it can reach Brobdingnagian (Gulliver found giants in addition to Lilliputians) dimensions; the record is 10 feet wide and 20 feet tall weighing about 5,000 pounds. [5] Two to three young eaglets hatch after about a month of incubation in their “McNest “and grow rapidly, fledging at 2 months, reaching full size in 3 months, and departing for a five-year odyssey that culminates in baldness. There is something almost human in the life and times of bald eagles.

The definitive Migratory Bird Treaty Act (16 U.S.C. §§ 703–712), was insufficient to protect important non-migratory species. Due to the transcendent importance of the national emblem and the awareness that their populations were continuing to plummet, the Bald and Golden Eagle Protection Act (16 U.S.C. §§ 668-668c), was enacted in 1940 as a supplemental act to prohibit the “taking” bald eagles, including their parts, nests, or eggs. [6] While restrictive legislation was necessary to save the bald eagle, it was not sufficient; by the 1960’s it was clear that extinction was not only possible but likely. Rachel Carson’s seminal 1962 book Silent Spring provided a possible cause in chapter 8, entitled “And No Birds Sing.” Based on a study of robin fatality that was attributed to eating worms that lived under elm trees sprayed with DDT conducted by Dr. Roy Barker of the Illinois Natural History Survey, she suggested a possibly link between eagle decline and insecticides: “Like the robin, another American bird seems to be on the verge of extinction. This is the national symbol, the eagle. Its populations have dwindled alarmingly with the past decade. The facts suggest that something is at work in the eagle’s environment which has virtually destroyed its ability to reproduce. What this may be is not yet definitely known, but there is some evidence that insecticides are responsible.” Her polemic arguments against the prevailing belief that “nature exists for the convenience of man” were profoundly influential; the Zeitgeist of the environmental movement was the ultimate result and DDT became the prime target, the Environmental Defense Fund its protagonist. [7]

The debate concerning the assignation of DDT as the cause of bird eggshell thinning has been loud, long and sometimes angry.  DDT was originally considered to be a great boon to mankind, so much so that the Swiss scientist Paul Müller was awarded the Nobel Prize in Physiology and Medicine in 1948 for discovering its insecticidal properties. It was used extensively in war-ravaged Europe and Asia to prevent typhus, malaria and dengue fever epidemics. The widespread use of DDT was preceded by a great deal of research on its effects by the United States Government and other institutions including universities and the agrochemical industry – it is a toxin after all. Initial tests, such as those by the Sanitary Corps of the U. S. Army which focused on the efficacy of chlorinated hydrocarbons in the eradication of insect pests such as head lice, concluded that DDT was among the best treatments due primarily to the fact that it persisted for long periods of time which would provide better pest management outcomes. This became the argument of the economic entomologists. It is a very effective insecticide; however, it is also toxic to many marine animals, notably fish.  DDT is an organochloride that readily breaks down into DDE which is a fat-soluble compound that builds up in body fat; it has a half-life of about ten years in human body tissue.  It is especially problematic to raptors like bald eagles that eat copious quantities of fish infested with DDT/DDE. [8] This was Rachel Carson’s thesis, which eventually led to the precipitous ban (with some public health exceptions) of DDT in the United States by the EPA in 1972, and by most other countries by the end of the 20th Century. In 2004, the Stockholm Convention (now ratified by 170 countries) established what would seem to be a reasonable middle ground:  DDT is “restricted for disease vector control.” [9] Whether or not DDT elimination played a significant role in the resurgence of bald eagles will likely never be fully resolved; regardless, it was a part of the change in emphasis toward environmental sustainment that clearly did have that desired effect.  The need for environmental protection that was first evinced by Teddy Roosevelt at the beginning of the 20th Century was made manifest by Rachel Carson at its middle; the century’s end marked a new beginning in the resurrection of the bald eagle; on 28 June 2007, it was removed from the federal list of threatened and endangered species. [10]

The bald eagle was chosen as the cynosure of the Great Seal of the United States by the Continental Congress on 20 June 1782. The symbolic importance of the seal to the idea of national sovereignty is manifest in its history; a committee composed of Benjamin Franklin, Thomas Jefferson and John Adams was appointed to submit a design on the 4th of July 1776, the same day that the Declaration of Independence was signed. The careful scrutiny that the seal design received resulted in six years of deliberation that culminated in the final selection: a bald eagle with a 13-stripe escutcheon clutching 13 arrows to symbolize war and an olive branch to symbolize peace beneath a 13-star constellation in the firmament to symbolize the rise of a new sovereign nation. [11] Paradoxically, the bald eagle, though central to the design, was not included in any preliminary drawings made over the six-year hiatus. It was only added at the very end by Charles Thompson, the Secretary of the Congress who was given all of the previous designs to propose a final version. While the reasons for his choice will never be known, his background as a Latin Instructor at Philadelphia Academy may provide a clue: the eagle has a long, and Latin, history. [12]

The eagle figures prominently in the history of western civilization as a symbol of power and authority. In Greek Mythology, an eagle named Aetos Dios was a companion and messenger to Zeus, the chief deity of their pantheon, immortalized in the constellation Aquila. That the eagle became the companion of Jupiter in the Roman version of theogony is quite likely the reason that the Roman legions chose the eagle, which won out over the boar, the Minotaur, the wolf and the horse, as the symbol borne atop their battle standard. After Rome divided and the Eastern Empire succumbed to the onslaughts of the gothic tribes in the 5th Century, the Western Empire became Byzantium, the bastion of Christianity. The Byzantine emperor adopted the double-headed eagle to symbolically represent the power of the state in matters both secular and religious. The double-headed eagle became the symbol of both the Holy Roman Empire (which Voltaire quipped was neither holy, nor Roman, nor and empire) and the Russian Empire, which considered itself “the third Rome” after Ivan the Great married Princess Zoe Paleologa, a Byzantine princess and niece of the last Byzantine emperor, Constantine XI. [13] And last but not least, the Eagle is the symbol of John the Evangelist and figures prominently as one of the beasts in the Book of Revelation. It is no wonder, really, why Thompson selected the eagle and that Congress, after six years and numerous attempts, voted in favor its centrality as a symbol to the newly united states that now became the United States of America. He had empires of eagles to draw on.

It is widely alleged that Ben Franklin favored the turkey as the national symbol. The calumny against the eagle as symbol is based on the documented opinion written by Franklin in a letter to his daughter Sarah Bache from Paris, France in 1784. He castigated the louche character of the eagle, a “bird of bad moral character” as “too lazy to fish for himself” citing that when a “diligent bird has at length taken a fish” then the “Bald Eagle pursues him and takes it from him.” However, this letter had nothing to do with the eagle of the Great Seal, but rather with the symbol of the Society of the Cincinnati, a newly formed group of served revolutionary war officers. Franklin generally abhorred pomp and circumstance and his trenchant wit as evidenced in his Poor Richard’s Almanac aphorisms, was apparent here. Noting that the Cincinnati eagle looked more like a turkey, he went on, in the same letter, to extol its virtues. In noting that the turkey is a “much more respectable bird” his sarcasm becomes evident with the notion that this “bird of courage … would not hesitate to hesitate to attack a Grenadier of the British Guards who should presume to invade his farmyard with a red coat on.”  [14]

References:

1. https://defenders.org/bald-eagle/basic-facts
2. Lewin, S “A Genetic Guide to Birds” Scientific American, April 2015 Vol 312 Issue 4.
3. Stalmaster, M.  The Bald Eagle. Universe Books, New York, 1987.
4. http://www.baldeagleinfo.com/
5. https://journeynorth.org/tm/eagle/NestAbout1.html
6. https://www.energy.gov/nepa/downloads/bald-and-golden-eagle-protection-act-16-usc-668-668c-and-related-regulations-50-cfr
7. Carson, R. Silent Spring, Houghton Mifflin Co. Boston, 1962, pp 103-127.
8. Davis F. Banned. A History of Pesticides and the Science of Technology, Yale University Press, New Haven, Connecticut, 2014.  A source book for the myriad studies of the effects of DDT on the environment.
9. https://www.epa.gov/ingredients-used-pesticide-products/ddt-brief-history-and-status
10. https://ecos.fws.gov/ecp0/profile/speciesProfile?spcode=B008
11. U. S. Department of State Bureau of Public Affairs. The Great Seal of the United States. Available at https://www.state.gov/documents/organization/27807.pdf
12. Patterson, R. and Dougall R. The Eagle and the Shield, A History of the Great Seal of the United States, U. S. Department of State Publication 8900 Released 1978, pp 92-102.
13. Dmytryshyn, B. A History of Russia, Prentice-Hall, New Jersey, 1977. pp 148 – 149.
14. Brands, H. The First American. The Life and Times of Benjamin Franklin. Doubleday, New York, 2000 pp 668 – 670.

Common Name: Ring-necked snake, ring snake, baby king snake, red-belly snake, yellow-belly ring snake – Even though the ring around the neck may be interrupted, obscured, or absent altogether, it is the most distinctive feature.

Scientific Name: Diadophis punctatus – The genus name is recognizable as a combination of the Latin word diadema, meaning “royal headband” (a diadem is a crown in English) and ophis, the Greek word for snake. The species name is from the Latin punctum, meaning point. In scientific names, it is used to indicate having small points or dots of color (punctate means “marked with dots or tiny spots” in English). A series of black dots extends along the underbelly.

Potpourri:  There are at least twelve subspecies of ring-necked snake, some of which don’t even have the characteristic ring around the collar. The designation subspecies is assigned when there is a difference in morphology, frequently only in coloration but inclusive of other variations in form or structure, usually resulting from geographic separation. Since subspecies are the same species, they can successfully interbreed but do so only if collocated in captivity. Geographic hybridization of snakes is not unusual, although twelve subspecies is outside the norm. The ring-necked snake’s neck ring can be yellow, cream, or orange, the underbelly can be red, yellow or orange, and the back can be gray, olive, brown, or black. Since none of these variants likely contribute to enhanced survival, random genetic variation amplified by inbreeding of isolated populations must be the main factor. The many subspecies result from a diaspora of the shared ancestral ring-necked snake that ranged across North America from Nova Scotia to the Florida Keys, west to the Pacific Coast, and south to Mexico. [1]

Ring-necked snakes are members of Colubridae, by far the largest family of the suborder Serpentes to which all snakes belong. Latin includes several words for snake, a likely result of the long-standing animus toward snakes only enhanced by the biblical account of Satan tempting Eve in the Garden of Eden. In addition to coluber, serpens names the suborder, vipera names the pit viper family Viperidae, and anguis is a genus of lizards called slow worms that have lost all vestiges of legs.  The range and diversity of colubrids, which comprise three quarters of all snakes in North America and the majority across the globe, was long thought to have been due to a dearth of research on snakes. Those snakes that did not fall into another, more obvious category like constrictors or vipers, were placed in Colubridae by default. However, most recent research using DNA associations has found that colubrids are monophyletic, evolving from a single ancestor. [2] This means that the evolution of the legless body plan that separated the snakes from the lizards must have been enormously successful ― that they took over a new ecological niche. The emergence of colubrids in the Oligocene Epoch about 40 million years ago just after the mammals expanded in range and numbers in the Eocene provides a logical hypothesis. Rodents living in holes breeding large populations of edible protein provided a resource nonpareil. Slithering, hole-diving lizards that lost their legs to become snakes were perfectly suited to exploit the resource. The Cenozoic Era is often called the Age on Mammals. “If the criterion were to be the most rapid adaptive radiation, the latter half of the Cenozoic would have to be called the Age of Snakes.” [3]

Ring-necked snakes are not rodent eaters. With an average length of twenty inches, mice are too large for their undersized maws. Like all snakes, they are obligate carnivores, ingesting their prey whole usually headfirst, down the gullet to the stomach for digestion ― a writhing esophagus. The brutal efficiency of the down the hatch method is impressive. A two-kilogram snake can ingest and digest prey weighing one kilogram. Black rat snakes range from five to eight feet in length … their name and girth reflect a penchant for the large rodents that they consume. Just as larger snakes evolved in perfecting mammal predation, smaller snake variants broke away genetically to exploit alternative food resource niches. Ring-necked snakes expanded across North America by consuming whatever they could find including insects, small lizards, earthworms, and amphibians. Five ring-necked snakes from George Washington National Forest were dissected in 1939 to reveal a diet that was 80 percent salamanders, 15 percent ants, and 5 percent other insects. This may explain why ring-necked snakes are considered the most common snake in Shenandoah National Park … it is well known as an epicenter of salamander diversity. [4] A preference for salamanders extends northward to Pennsylvania, where a more recent study of 58 northern ring-necked snakes (D. p. edwardsii) found that their primary food was plethodontids, lungless salamanders. [5] Salamanders are masters of concealment with cryptic colors and concealed hideaways under rocks … finding them is challenging. Ring-necked snakes employ chemical sensors as vectors to seek them out. They don’t need to be successful too often, since each meal results in a gain of one gram for every three grams consumed. One or two salamanders a month is plenty for the cold-blooded. [6]

Since snakes lacked bodily appendages for tearing and clawing, the mouth became essential as a weapon with only constricting body coils as backup. Trying to pin down a struggling if hapless victim to position them for swallowing without the restraining benefit of clasping limbs is surely daunting if even possible. It is also not without some danger to the predator, as rats are vicious when cornered.  Some snakes evolved muscular bodies, using brute force to literally choke the life out of their prey. Others randomly mutated to produce chemicals in glands surrounding the oral cavity that assisted in some degree toward prey immobilization. In extreme cases, these concoctions are deadly, injected with the fangs that project from the front of the mouths of vipers. Snake venom is a complex of up to 100 proteins that is stored in venom glands that can take several days to replenish once the supply is exhausted.  Since the means to kill is vital to viper survival, venom is meted out with care, apropos to prey size and injected through ducts in piercing front teeth at high pressure. This allows for the real possibility that multiple strikes may be needed to land a coup de grâce bite.[7]  The ring-necked snake is one of many colubrid snakes that are called rear-fanged. Rather than delivering a thrusting, two-tooth attack like their viperous cousins, they deliver a smaller dose of less potent venom. Limited research has been done on the composition of colubrid venoms, but it has been demonstrated that some affect only birds and lizards with little to no effect on rodents. This supports the general hypothesis that the mutation that led to snakes producing the proteins from which venom  is concocted occurred only once and that protein synthesis over time based on types of the prey encountered resulted in specialization. However, the complexity of venom glands and the great diversity of venom composition suggest multiple introductions by different clades. Speculation is the handmaid of scientific study.

Ring-necked snakes produce venom in two glands named for the French zoologist who first noted them during a snake dissection. The full biological function of Duvernoy’s gland is not yet known, although it is certainly for some type of trophic (nutrition related) purpose. There are multiple glands located around a snake’s oral cavity that are necessary to carry out the incongruous process of swallowing oddly shaped objects that can be twice the size of the hole they go into. Lubrication is necessary to slide the jaws slowly forward and digestive enzymes need to start immediately in breaking down skin and muscle tissue. Of course, it helps to kill the prey first.  Duvernoy’s glands are located directly behind the eye near the top of the skull and drain through ducts into grooves in posterior maxillary teeth, the so-called rear fangs, homologous to the venom glands of vipers.  However, rather than the lighting strike stab of vipers, ring-necked snakes use partial constriction to hold their prey while they bite down, injecting venom through multiple puncture wounds.[8] There is ample evidence that ring-necked snake venom is effective. In one experiment, garter snakes were injected with the oral secretions extracted from ring-necked snakes. They all died withing three hours. [9] Humans are not immune. A researcher was handling a ring-necked snake to take a picture when it bit him on the finger. The sharp, sting-like pain was immediate, followed within minutes by swelling of the finger that spread to the entire hand. Over the next 24 hours, redness spread down the finger from the puncture wound which persisted for the next three days. [10] There are about 700 rear-fanged colubrid snakes that produce some kind of venom which means that these so-called “harmless snakes” are not (harmless).

Ring-necked snakes occupy an elevated position in the food chain, but they do have predators. In addition to a variety of other snakes, raccoons, opossums, skunks, owls, and black bears all routinely prey on ring-necked snakes. If juveniles are included, the predator list extends to toads, shrews, and even large spiders and centipedes. Since females lay no more than ten eggs a year with no parental care thereafter, an attrition rate of about ninety percent is nature’s expectation. However, ring-necked snakes are relatively successful in spite of their small size, as evidenced by their widespread radiation across the continent and their relative density in wooded habitats. They are found frequently in communal groups with up to nine individuals. [11] The higher-than-expected survival rate can be attributed to several behaviors employed to ward off predators. The most notable is turning upside down in a writhing corkscrew movement, an eye-catching display of brightly colored red or orange belly scales. The use of bright colors as deterrent is called aposematism, the opposite of camouflage in that it intentionally draws attention rather than conceals. It is typically employed by otherwise defenseless animals that have poisonous secretions like monarch butterflies and red eft juvenile newts. The aposematic use of reds and oranges is intended to deter birds as they have full color vision whereas mammals see only blues and greens (primates are the only exception). Since ring-necked snakes lack poisonous secretions and since most of their predators are mammals and can’t see red anyway, the “colorful corkscrew” defense cannot be aposematic. It is more likely a surprise maneuver meant to throw an assailant off balance, retreating in the face of an uncertain threat. Some of the less colorful ringneck subspecies also play dead and emit mephitic odors as deterrents, relying on the near universal (vultures excepted) aversion to a rotting and possibly toxic meal.

So what about the namesake neck ring? With all of the aforementioned machinations to ward off predation, why would a conspicuous and contrasting bright yellow ring adorn the otherwise cryptic gray-brown of the dorsal surface? It is undeniably an adaptive mutation that must have had purpose that led to its spread and retention in the diverse populations. Group identification and sexual selection are both implicated by behavior. The neck ring could then serve as a clear “friend or foe” visual indication to promote group cohesion. Ring-necked snakes are very sociable, sometimes living in colonies with up to one hundred individuals. A number of larger snakes that are similarly colored but without the ring prey on ring-necked snakes. The benefit that they gain by living in communes is speculative, but it  must be related to enhanced survival comparable to birds in flocks and fish in schools. Larger groups also provide more opportunities for opposite sexes to meet and mate enhancing sexual selection. The neck ring could also function as a colorful beacon of sexual fitness. Male ring-necked snakes are attracted to females releasing fertility pheromones.  While only a small number of sightings of ring-necked snakes mating have been recorded, males have been observed rubbing their closed mouths over the female body followed by biting around the neck ring just before copulation. [12] Foreplay is what some sociable animals do. Sociable snakes?

Lastly we return to the subject of subspecies and zoology. What is the purpose of having over twelve ring-necked snake subspecies?  They differ in morphology attributable to  the geographical radiation of the species. Many are distinguished by the number and distribution of black dots that adorn the underbelly. The black dot configuration may have some physiological function but it is unclear what that might be.[13] The relative rarity of an individual subspecies would not correlate to endangerment because the overarching concern of species extinction is the loss to the biological gene pool. Subspecies can mate with each other to reproduce the baseline DNA codon protein programming of the species. All domestic dogs are Canis familiaris. They range in size and shape from Great Dane to  Chihuahua, and aside from the acrobatics that may be required, they could mate and produce offspring that would be some combination of the two. Using the rules applied to snakes, all dog breeds would all be separate subspecies. And what about Homo sapiens? When Carolinus Linnaeus introduced the binomial name for humans in the tenth edition of Systema Naturae in 1758, he identified four varieties: Europaeus, Asiaticus, Africanus, and Americanus. These were the original subspecies that became the foundation for the current racial distinctions [14]. The idea of subspecies is not an altogether helpful concept sociologically. It is not unreasonable to question its usefulness to biology.

References: 

1. Behler, J. and King, F. National Audubon Society Field Guide to North American Reptiles and Amphibians, Alfred A. Knopf, New York, 1979, pp 589-679.

2. Zheng, Y., Wiens, J.  “Combining phylogenomic and super matrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species” Molecular Phylogenetics and Evolution 8 October 2015. http://www.wienslab.com/Publications_files/Zheng_Wiens_2015b_MPE.pdf     

3. Starr, C. and Taggart, R. Biology, Wadsworth Publishing, Belmont, California, 1989, p 585.

4. Linzey, D. and Clifford, M. Snakes of Virginia, University Press of Virginia, Charlottesville, Virginia, 1981, pp73-77.

5. Cathro, Andrew and Lindquist, Erik 2016. Diadophis punctatus edwardsii (Northern Ring-necked Snake) Diet. Herpetological Review 47 (4): 681

6. Henderson, R. “Feeding Behavior, Digestion, and Water Requirements of Diadophis punctatus arnyi Kennicott”. Herpetologica. 1970, Volume 26 Number 4 pp 520–526.

7. Kardong, K.  Colubrid snakes and Duvernoy’s “Venom” Glands .Journal of Toxicology: Toxin Reviews. 6 December 2002, Vol. 21 No. 1 pp 1–15.

8. Mackessy, S. and  Saviola, A. “Understanding Biological Roles of Venoms Among the Caenophidia: The Importance of Rear-Fanged Snakes” Integrative and Comparative Biology. 1 November  2016 Volume 56 Number 5 pp 1004–1021.

9. O’Donnell, R. et al. “Experimental evidence that oral secretions of northwestern ring-necked snakes (Diadophis punctatus occidentalis) are toxic to their prey”. Toxicon. November 2007, Volume 50 No. 6 pp 810–815.

10. Brock, T. & Camp, C.  Diadophis punctatus edwardsii (Northern Ring-necked Snake) Envenomation. Herpetological Review 2018 Volume 49 Number 2 pp 340-341.

11. Blanchard, F. et al “The Eastern Ring-Neck Snake (Diadophis punctatus edwardsii) in Northern Michigan”. Journal of Herpetology. 15 November 1979 Volume 13 No. 4 p 377.

12. Yung, J. Diadophis punctatus University of Michigan Museum of Zoology  https://animaldiversity.org/accounts/Diadophis_punctatus/   

13.  http://reptile-database.reptarium.cz/species?genus=Diadophis&species=punctatus   

14. Graves, J. and Goodman, A. Racism, Not Race, Columbia University Press, New York, 2022. Pp 3-4.

Common Name: Eastern redcedar, Red cedar, Red juniper, Cedar apple, Virginia red cedar  – Cedar is from kedros, the name for the tree in Greek, which probably is derived from kadru, Sanskrit for tawny. Cedar trees were well known in antiquity and their aromatic wood was renowned throughout the Mediterranean region. The bark is red-tinted, the “red” distinguishing it from the lighter colored white cedar. The tree is indigenous to the eastern half of North America as the counterpart to the western redcedar.

Scientific Name: Juniperus virginiana – The generic name is the Latin word for juniper, a shrubby evergreen of the northern latitudes, also well known in antiquity. The etymology is unclear but it may originally have come from a word for reed or stem to describe the twiggy leaf structure. The tree was first encountered by European naturalists in the colony of Virginia.

Potpourri:  The Eastern redcedar is the most widely distributed conifer in the Eastern United States. It has two starkly contrasting reputations. On the positive side, it has historically been considered one of the most important indigenous trees in North America with multiple uses among native peoples. As a curative agent, a ready source of wood, and an insect repellent, it permeated Indian culture which was largely adopted by the pioneering Europeans as they moved inland and learned to endure the same hardships. Red cedar was therefore an equally important mainstay of early settler homesteads east of the Mississippi River, sought after for its valuable commodity assets.  In the modern era that spans the last century, it has taken up a more sinister role as a scruffy roadside eyesore, rising to near invasive status in many disturbed areas. It occupies monoculture stands along major highways, challenged only by the equally prolific Ailanthus/tree of heaven. However, there is a qualitative difference between an invasive alien and a widespread native. Introduced plants like Ailanthus invade new habitats free of local predators and devoid of competition to dominate the sun’s energy and the soil’s nutrients. Indigenous plants like Eastern redcedar that have evolved to thrive on meager resources in hardscrabble environments are honest competitive pioneers.

Eastern redcedar also has a split personality by name ― it is a juniper and not a cedar. However, it is literally a family affair since both cedars and junipers belong to Cupressaceae, the resinous evergreen family of trees and shrubs commonly called Cypress. With about 130 species worldwide, cypresses are characterized by scalelike leaves in flattened twigs, unlike the needles of pines, hemlocks, and firs. [1] The cedar name preference was likely a result of English colonists whose religious affiliations would have favored a common tree name with more biblical resonance. While the juniper is mentioned in the bible, the cedar is literally foundational; King Solomon built the temple in Jerusalem from the Cedars of Lebanon (Cedrus libani). A cursory inspection at the fruiting time of year would have revealed the error; junipers have “berries” and cedars do not. In reality they are not berries but small, round, dark blue cones ― verisimilitude by design. Since both berries and cones are the fruiting bodies of their respective plants and carry the all-important seeds, convergent evolution favoring propagation is evident.

Conifers have cones and evergreens are always green. However, not all conifers are evergreen. The larch and the bald cypress are deciduous, losing all their needles annually. Conifers are gymnosperms of the order Pinales. Gymnosperm literally means “naked seed,” distinguishing them from the angiosperms with seeds encapsulated in a developed ovary ― fruit like an apple or peas of a pod. The angiosperms are the most advanced land plants, their survival enhanced by sweet tasting fruit attracting animal herbivores that spread reproductive seeds to germinate in nutrient-laden fecal droppings. Naked seed plants, lacking fruited ovaries, usually produce robust cones. Cones come in two types: male pollen cones and female seed or ovulate cones. Most conifer trees are dioecious, with a single tree producing both male and female cones. [2] The Eastern redcedar is monoecious in having separately sexed trees. Male tree pollen cones are ephemeral, forming upright structures called staminate strobili or conelets that release clouds of wind-borne pollen in spring of which a vanishingly small percentage will land on the ovaries of downwind female tree ovulate cones.  The tough, woody ovulate cones of most conifers are a palladium for the development of the fertilized seed on which the future of the plant ultimately depends, their naked seeds dispersed and carried away by the wind or dropped to the ground below. However, in the case of the Eastern redcedar, green scales form as an outer protective coating over an unusual non-rigid, berry-like cone. As the season progresses, the color of the “berry-cone” changes from greenish white to a distinctive blue when mature, mimicking the progression of flowering plant berries from green to red or blue-black. [3] Not all evergreens have cones either. Holly, mountain laurel, and rhododendron retain non-needle leaves perennially. The cedar cum juniper is a full-fledged evergreen conifer … both attributes have purpose.  The environmental factors that contribute to the prevalence of evergreen over deciduous growth are related to sun and soil nutrient resources. At high elevations and northern latitudes, the growing season insolation is insufficient for the annual regrowth of leaves in time to absorb enough sun energy for sustainment. Equally, poor soils with diminished nutrients cannot support annual leaf regeneration. Nature’s answer to not being able to grow a new set of leaves every year is to keep them so that the tree is always, that is ever, green. The preponderance of narrow leaf shapes like pine needles and cedar scales is related to both water retention, as reduced surface area equates to less evaporation, and resistance to storm and snow weather damage in winter when other trees are bare. Evergreen trees do replenish their greenery like their broadleaf cousins, but they do so incrementally rather than all at once. The needles of pine trees are replaced about every four years while those of cedars and junipers are on a roughly ten-year cycle. [4] Eastern redcedar thrives in marginal soil habitats, encroaching on grasslands that are essential to livestock operations.  For example, it is estimated that over seven hundred acres of rangeland are lost every day in Oklahoma due to Eastern redcedar. [5] While this has understandably raised the hue and cry of the cattle-beef industry, anything that cuts back on the contribution of methane belching cows to climate change is at worst equivocal. Long term research studies have revealed that “encroachment by J. virginiana into grasslands results in rapid accretion of ecosystem C and N in plant and soil pools.” [6] In other words, “invasive” red cedars not only sequester carbon but crowd out cows, doubling their greenhouse gas reduction efficacy.

There is one characteristic of red cedar range expansion that weighs against its otherwise positive environmental credentials. As an integral partner in a ménage à trois with a fungus that involves apple trees, cedars are complicit in crop damage. Fungi developed some peculiar relationships with plants as they evolved in the dark backwaters of the ecological web. One of the most interesting is heteroecism or two host parasitization. Eastern redcedar trees are linked to apple trees by a fungus aptly named Gymnosporangium juniperi-virginianae, which is commonly called cedar apple rust. The biennial cycle starts as the fungus forms mycelial galls on the tips of red cedar branches. The mycelium is the main body of the fungus. In spring, hornlike projections grow outward from the gall bearing billions of red-orange spores. The windborne spores are carried aloft and afield ― a miniscule percentage will land on apple (and crabapple) trees, where they germinate.  Yellow spots appear on the apple tree’s fruits and leaves the following spring from which a second set of spore bearing tube-like structures release spores that germinate only on red cedar leaves. That one fungal species requires two alternating hosts to survive is not unique. Barberries and wheat are conjoined in a similar arrangement with wheat rust. [7] Why and how this duality evolved is a matter of some conjecture, but it is quite true that the fungus can be eradicated by getting rid of one of the two hosts, as was done with barberry. Due to the expansive nature of red cedar, it is impractical to remove trees. Fungicides and planting rust-resistant apple varieties are the primary remediation practices.

The seeds of Eastern redcedar enclosed in “angiosperm-like” cones mimic the berries that attract animals, especially birds. The cedar waxwing is named for its preference of these “juniper berry” fruits. Field studies have found that it takes about twelve minutes for the juniper berry and its seeds to pass through the avian digestive tract and that the seed thus “processed” has a germination probability that is three times that of a berry-cone seed that simply falls to the ground (as all uneaten cones eventually will). It is in this manner that Eastern redcedar extends along rural fence lines which serve as roosts for engorged cedar waxwings. Juniper berries are also a popular food source for many other birds including robins, ruffed grouse, and turkeys as well as small mammals like raccoons, skunks, and opossums. [8] The evident desirability of Eastern redcedar cones by diverse animal populations is indicative of some evolution of the former to suit the latter. With high concentrations of fat and fiber, moderate levels of calcium, and, most importantly, substantial carbohydrates for metabolic energy, they are excellent sources of nutrition.  However, just because animals eat them does not mean that humans can. Juniper berry edibility is tenuously acceptable according to which of the thirteen different species of juniper is ingested. However, juniper berries are mostly too resinous for human tastes, suitable only for seasoning or perhaps for tea when roasted and ground. The flavor of the berries is distinctive. The French name for juniper is genièvre from which gin, a liquor flavored with juniper berries, derives.[9]

Eastern redcedar was widely used by Native Americans according to region and tribal customs. The leaves and twigs of the tree were steeped in water to extract chemical constituents as a ptisan, a natural tea administered orally for the treatment of respiratory ailments like colds and coughs by Cherokee, Cheyenne, Flathead, Nez Pierce, Sioux and the Haudenosaunee or Iroquois Confederacy. The aromatic properties of cedar were volatized by burning, the incense an important part of Kiowa prayer meetings, Lakota funerals, and a treatment to reduce Seminole anxiety. The wood, with its inherent resistance to decay and insect infestation, was used by Ojibwa for wigwam construction, Navaho for a war dance ceremony wand, and among various tribes for everything from musical flutes to canoes.[10] The use of red cedar by American colonists based on Indian antecedents was well established by the 18^th century as noted by  Swedish botanist Peter Kalm in 1749 on occasion of his North American travels. He chronicled that it was among the most durable of all woods used in home and boat construction, and that “some people put the shavings and chips of it among their linen to secure it against being worm eaten,”  the origin of the cedar chest. [11] Institutional medicinal applications of cedar became were well established by the 19^th century; it was listed as a diuretic in the U. S. Pharmacopeia from 1820 to 1894. Oil of cedar, sometimes called cedarwood oil, has been included a reagent in the Pharmacopeia since 1916 and is used in aromatherapy and as an insect repellent. [12]

Juniperus virginiana is notably successful as a matter of natural resilience in its production of chemicals that protect it from everything from microbe attack to insect maceration. These properties, moderated by limited dosage, are the basis for its use to ameliorate human health by arresting bodily access by biotic invaders.  One of its constituents is podophyllotoxin, the name derived from the genus Podophyllum peltatum commonly called mayapple, from which it was first isolated. It is currently prescribed for use as an antiviral topical treatment of genital warts with many emerging applications ranging from cancer and multiple sclerosis to arthritis and psoriasis. [13] There is also something to the documented use of the soothing smell of cedar as a treatment for anxiety by Seminole herbalists. Testing with laboratory mice has shown that cedrol, one of the constituents of cedarwood oil, produces anti-anxiety or anxiolytic effects measured by performance in maze behaviors. Physiologically, it increases the amount of dopamine, a neurotransmitter known for its positive behavioral effects. [14] Cedar wood and juniper berries as insect repellent are equally valid according to recent research. The resinous exudate of its berries have antiparasitic and nematicidal (worm killing) properties and its wood resin is antibacterial. [15] Eastern redcedar/juniper is a tree for all seasons, but especially Christmas, with cedar apple rust ornaments to boot.

References:

1. Little, E. The Audubon Field Guide to North American Trees, Alfred A Knopf, New York, 1986, pp 305-315.

2. Wilson, C. and Loomis, W. Botany, 4th Edition,  Holt, Reinhart and Winston, New York, 1967. pp 549-570.

3. United States Forest Service database https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/juniperus/virginiana.htm   

4. Kricher, J. and Morrison, G. Peterson Field Guide  to Eastern Forests, Houghton Mifflin Company, Boston, 1988, pp 8-9, 279.

5. https://www.noble.org/news/releases/oklahoma-must-address-cedar-encroachment/ 

6.  McKinley, D.; Blair, J. “Woody Plant Encroachment by Juniperus virginiana in a Mesic Native Grassland Promotes Rapid Carbon and Nitrogen Accrual”. Ecosystems. 1 April 2008 Vol. 11 No. 3: pp 454–468. 

7. Stephenson, S. The Kingdom Fungi, Timber Press, Portland, Oregon, 2010 p.182.     

8.   Barlow, V. “Eastern Redcedar, Juniperus virginiana”, Northern Woodlands, Winter 2004 https://northernwoodlands.org/articles/article/eastern_redcedar_juniperus_virginiana/   

9. Angier, B. Field Guide to Edible Wild Plants, Stackpole Books, Mechanicsburg, Pennsylvania, 2008, pp 110-111.    

10. Native American Ethnobotany Data Base. http://naeb.brit.org/uses/search/?string=juniperus%20virginiana&page=1

11. Kalm, P. Travels into North America; Containing Its Natural History, and a Circumstantial Account of Its Plantations and Agriculture in General, with the Civil, Ecclesiastical and Commercial State of the Country, the Manners of the Inhabitants, and Several Curious and Important Remarks on Various Subjects. 1772. Translated into English by John Reinhold Forster. Vol. 1 (2nd ed.). London: Printed for T. Lowndes, No. 77, in Fleet-street.

12. USDA Plants Data base. https://plants.sc.egov.usda.gov/home/plantProfile?symbol=JUVI  

13.  Cushman, K. et al “Variation of Podophyllotoxin in Leaves of Eastern Red Cedar (Juniperus virginiana)”. Planta Medica May 2003. Vol. 69 No. 5 pp  477–478. 

14. Zhang, Kai; Yao, Lei “The anxiolytic effect of Juniperus virginiana essential oil and determination of its active constituents”. Physiology & Behavior May 2018  Vol. 189  pp 50–58.

15. Samoylenko, V. et al “Antiparasitic, nematicidal and antifouling constituents from Juniperus berries”. Phytotherapy Research. December 2008.  Vol. 22  No. 12 pp 1570–1576.

Common Name: Great Lobelia, Gagroot, Asthma weed– Use of the scientific genus for a common name is not unheard of in botany, but it is unusual. It would be logical but wrong to associate the name with “lobe,” a round projecting part like those of the multi-petal blossom. Since common names arise randomly as mnemonics, it is probable that the “lobe-like” name was good enough. The true etymology of the common/genus name is to honor Matthias de l’Obel, the sixteenth century Flemish physician to both Prince William of Orange and King James I of England. The two other notable flowers in the genus Lobelia that are of special note have more descriptive common names: Cardinal Flower, and Indian Tobacco.

Scientific Name: Lobelia siphilitica – The species name is recognizable as a Latinized version of syphilis, the (mostly) sexually transmitted disease (STD) that was the scourge of Europe in the sixteenth and seventeenth centuries. The plant was at one time considered a curative.

Potpourri:  The “Great” Lobelia deserves the honorific reserved for historically important leaders like Alexander and imposing pyramids like Khufu by virtue of its superlative floral attributes. Up to four feet tall, it is liberally spangled with clusters of irregular blue flowers that extend outward in five pointed lobes like grasping, gloved fingers. The name lobelia evidently stuck as it is overendowed with lobes even though that has nothing whatever to do with the name, which honors the Flemish physician Matthias de l’Obel (“de le” is ”of the” in French) who wrote several books on botany with emphasis on medicinal properties. This is apropos as the other  common names gagroot and asthma weed are evidence of a deep relationship that people have historically had with this plant and its several cousins. The lobelias are producers of some potent chemicals that have historically been subject to diverse herbal remedies for maladies both real and imagined, syphilis is just one of them.

The lobelias are in the Bellflower Family Campanulaceae (campana means bell in Latin), named for the prevalence of radially or bilaterally symmetrical tubular bell-shaped flowers. With the exception of the bright red Cardinal flower (L. cardinalis), most range in color from lilac to blue.[1] Since the function of flowers is to attract mobile animals to sessile plants to transport male pollen from one to the female stigma in another, different colors and shapes can only have evolved for that purpose. Differences in color are especially noteworthy when two species in the same genus have a common origin and physiology but only differ markedly in hue. A vivid, eye-catching red was chosen for the color of the robes of the highest officials in the Roman Catholic Church below the pope who were cardinalis, Latin for principal. The name as color carried over to the bird and flower without ecclesiastical implications. The cardinal flower can only have evolved to attract a specific type of pollinator … perhaps a single species.  Lobelias with their drooping tubular bluish flowers are well suited for bee pollination. Bee vision extends through the blues to the ultraviolet range but they cannot see red. Cardinal flowers grow in boggy habitats in dense stands, evidence of multiple germinations at the same location. They are frequently attended by  butterflies flitting from flower to flower, especially spicebush swallowtails. It is quite probable that this has something to do with the color, which is attractive to butterflies while unseen by bees.

The purpose of sex is genetic diversity, a simple fact often misconstrued in the neo-culture of gender preference, both real and perceived. Nature goes to great lengths to ensure that genetic DNA is mixed and matched to produce the variation on which adaptability depends. The fossil record is a road map of what has and has not been able to change to meet new environmental challenges such as that induced by a meteor crashing into the earth near Chicxulub, Mexico 65 million years ago. Floral diversity can only be achieved via transport of male gametes from one plant to the female gamete of another. Dioecious species like maple and holly trees have a male plant and a female plant to promote diversity. Monoecious species like lobelias that have both sexes on the same plant are more common. Since the stamens of a flower that contain the male pollen are situated adjacent to or directly over the female pistil, self-pollination instead of the preferred cross-pollination would be the more likely outcome absent some evolutionary legerdemain. The term proterandrous, literally “before-male,” applies to lobelias. It means that a flower’s male pollen reaches sexual maturity before the female stigma is receptive. A pollinator would then be more likely to carry pollen from one flower with stigma deactivated to another that is receptive. Several days after opening, the stigma curls backward to come in contact with pollen dropped into the base of the flower from its own anthers. This functions as a backup, promoting self-pollination should pollinators fail to deliver. This then would assure survival although lacking the genetic diversification of DNA contributions from two different plants. [2]

In order to mature to reproductive age and produce seed for future generations, plants must survive to sexual maturity. Chewing insects and browsing herbivores must therefore be held at bay. This is the basis for spines and thorns that keep animals away but also for the chemistry of taste and aroma as deterrents. Plants evolve random mutations to create compounds against specific threats. The toxic “milk” in milkweed is exuded when the stem is punctured to keep sap-sucking bugs away. Some animals adapt to tolerate these toxins to employ them as their own deterrents. Monarch butterfly larvae that eat milkweed are a good example, as both the caterpillar and the adult gain the advantage of the plant’s poisons to escape predation. In a similar vein, herbal medicine is the use of plant produced chemicals to promote human health. The difference is sentience … herbs are chosen for specific conditions based on human knowledge. Since the Great Lobelia is named L. siphilitica, syphilis provides a good case in point. The disease first appeared in Italy in 1494, infecting many of the French soldiers besieging Naples who spread it throughout Europe as “the French Disease.” The name syphilis comes from an epic poem attributing the disease to a shepherd named Syphilus who had offended the god Apollo. As punishment, “A hideous leprosy covers his body; fearful pains torture his limbs and banish sleep from his eyes.” [3] It was the scourge of Europe in the 18^th and 19^th centuries, infecting many notable composers, philosophers, and musicians including Mozart and Beethoven. [4]  

Syphilis is caused by Treponema pallidum, a spirochete closely related to the microbe that causes Lyme Disease which has similar symptoms. It is spread mostly through “intimate sexual contact,” the coarse vernacular now only too common. It was almost certainly imported from North America by lascivious Columbian mariners debarking in Italy. Bone samples that pre-date any association with Europeans confirmed that the disease occurred in Native American populations. The debilitating consequence of syphilis as it spread unchecked through the upper echelons of European society (one need not wonder why) precipitated a pressing need for treatment. Before the age of pharmaceutical drug trials, the only option was to identify a naturally occurring compound by trial and error; searching in North America where it started was the logical thing to do. Herbalists who had begun to study the unique flora of the New World in the eighteenth century working on occasion with Native Americans learned of a treatment for syphilis using lobelia plants. [5] By the time that Carolinus Linnaeas started cataloguing plants by genus and species in about 1735, the use of lobelia plants for treating syphilis had been well established ― enough to warrant assigning the scientific name Lobelia siphilitica. The fact that the treatment ultimately failed to cure the disease in Europe was attributed to deterioration of the relevant lobelia compounds on the long sea voyage. [6] It is much more likely that it didn’t do much good for the Native Americans either. 

The several species of flowers in the genus Lobelia were used for a wide variety of treatments by different tribal groups as a matter of local lore and cultural practice. The Iroquois, a confederation of six tribes in the northeast, used parts of the roots and stems of the cardinal flower for just about everything, considering it a panacea by itself but also as a complimentary adjuvant when mixed with other herbs. It was even taken for sickness (presumably depression) caused by grieving. The Cherokee, native to a vast territory comprising a large portion of the southeast, were more selective, using lobelia compounds for specific ailments like fever, rheumatism, and stomach problems. That they diagnosed and treated the disease called syphilis with lobelia is likely the fons et origio of its purported curative power. The Cherokee are also closely associated with a third species of lobelia called Indian Tobacco (L. inflata). The common name implies that it was used as a substitute for tobacco (genus Nicotiana from which nicotine is derived) which was widely used by native peoples throughout the Americas. According to the historical record, however, it was used as a substitute for tobacco in order to break the nicotine habit and not as an alternative. [7] There would be no need for a tobacco substitute as it was quite common. Indian tobacco was also used medicinally as a strong emetic, which is appropriate, since it has the highest concentration of the “medicinal” compound shared by all lobelias.

The efficacy of historic herbal remedies such as lobelia extracts can only be determined using science-based methods to distinguish snake oil from bonafide medicine. However, it is almost never cost effective to do so since human trials are exorbitantly expensive and wild plants are free. It is well established that the effective chemical in lobelia plants is an alkaloid named lobeline according to generic custom. It is similar in structure to nicotine, producing commensurate physiological effects. Lobelia extracts have been used in a variety of products like chewing gum and patches marketed to break the tobacco habit, emulating the Cherokee practice. In nineteenth century America, when treatment options were primarily limited to extracts from plants and animals, lobeline was one of the most popular. The common names gagroot and pukeweed suggest that it was often used as an emetic. This should not come as much of a surprise, because ingesting a poison is almost certain to induce the stomach to eject it along with everything else. There are anecdotal suggestions that death may have resulted from using lobelia as a home remedy. [8] Recent research has shown that herbal supplements, lobeline among them, can have adverse cardiovascular effects, particularly when used in combination with other drugs. [9]  While there has also been some research with animals to attempt to validate lobeline as a viable drug, the current consensus in the medical community is that “lobelia is not effective for smoking cessation, asthma, or any other medical condition..” [10] However, the jury is still out on lobeline, which has been shown to improve patient response to multi-drug resistance, a problem in chemotherapy.[11]  It is fair to conclude that Native Americans were onto something whose full potential has yet to be realized. Perhaps one might look to the Meskwaki Indians for inspiration. They used chopped up lobelia sprinkled in food or on beds of discordant couples as a means of easing marital discord. [12] It would likely not be too difficult to recruit drug trail participants for a love potion.

References:     

1. Niering, W. and Olmstead, N. National Audubon Society Field Guide to North American Flowers, Alfred A. Knopf, New York, 1998 pp 438-442

2. Gadella, T. W. “Campanulales” Encyclopedia Britannica, Macropedia William Benton Publisher, Chicago, 1974, Volume 3 pp 704-708.

3. Fracastor, Hieronymus, Syphilis, The Philmar Company, St. Louis, Missouri 1911. pp 1-58.

4. Franzen, C. “Syphilis in composers and musicians – Mozart, Beethoven, Paganini, Schubert, Schumann, Smetana”. European Journal of Clinical Microbiology & Infectious Diseases. 1 July 2008 Volume 27 No. 12 pp 1151–57.

5. Foster, S. and Duke, J. A Field Guide to Medicinal Plants and Herbs, Houghton Mifflin Company, Boston, 2000. pp 163-164.

6. http://naturalmedicinalherbs.net/herbs/l/lobelia-siphilitica=great-blue-lobelia.php  

7. Native American Ethnobotany Database at http://naturalmedicinalherbs.net/herbs/l/lobelia-siphilitica=great-blue-lobelia.php   

8. Foster, op cit.

9. Cohen, P. A.; Ernst, E. “Safety of herbal supplements: A guide for cardiologists”. Cardiovascular Therapeutics. August 2010 Volume 28 Number 4 pp  246 – 253.

10. Memorial Sloan Kettering Cancer Center. https://www.mskcc.org/cancer-care/integrative-medicine/herbs/lobelia   

11. Ma Y. “Lobeline, a piperidine alkaloid from Lobelia can reverse P-gp dependent multidrug resistance in tumor cells”. Phytomedicine. 15 September 2008 Volume 15 No. 9 pp 754–758.

12. Harris, M. Botanica, North America, Harper Collins, New York, 2003, p 89.

Common Name: Wood Frog – Frog is among the oldest of Indo-European words originating as the Sanskrit pravate, meaning “he jumps up.” It evolved to English through Old Norse as frauki. Wood frogs are found around wet areas in woodland habitats, but not on wood as the name suggests. The reference may be to its characteristic brownish hues which are similar in color to wood bark. However, brown frog would then be a better choice and no less uncreative.

Scientific Name: Rana sylvatica – Rana is the Latin word for frog which differs from the Sanskrit origin as an onomatopoeia of their call …  like croak or ribbit in English. The Latin word for woodland is silvae. The scientific name is literally “frog wood,”  the opposite of the common wood frog name. Wood frog have been reclassified by modern DNA taxonomy to Lithobates sylvaticus from the Greek lith meaning “stone” and bates meaning “one who treads,” which would connote “stone walker.” This could be literal, as is the case for the wood frog depicted above climbing on a lichen-covered rock.

Potpourri:  Wood frogs appear in the spring after having endured even the coldest of winters as if immigrating from remote, warmer habitats, like anuran snowbirds. Surely an amphibian noted for its slimy wetness cannot have survived near frozen-through skateable ponds that dot the woods they inhabit. But they do. The extraordinary tenacity of life in the savagery of the wild is the result of the survival of mutants.  After the basics of what it took to be a frog were successfully worked out in the deep recesses of time, populations of jumping, amphibian carnivores lurking in or near water burgeoned. To escape the crowds competing for the same resources, the more adventurous individuals left for greener, but sometimes colder, pastures. The resulting diaspora to new environments is one driving force for speciation. Wood frogs, like humans among mammals, have managed by sheer luck to evolve in the right direction to become among the most successful of their amphibian cohorts. Not only do they survive arctic winters, but they are first to emerge in spring to fill any emergent pool of water with thousands of eggs. It is only a matter of time until a new mutation will offer better chances elsewhere.

The first question is how do thin-skinned animals survive iced-in ponds without the coat of a beaver or down like a duck? This conundrum perplexed naturalists whose warm blooded judgement was skewed toward bears denning in caves and caribou gathering in tightly packed  herds to share or conserve body heat. The cold blood of reptiles and amphibians lacks the metabolic wherewithal of thermoregulation. Consensus was that burrowing deep into the ground below the frost line was the only possible palladium; toads had been found buried up to four feet deep during excavations.  John Burroughs, an eminent nineteenth century American naturalist, chanced upon a frozen frog he found under some leaf litter and concluded that “… frogs know no more about the coming winter than we do, and that they do not pass deep into the ground to pass the winter as has been supposed.” [1] Finding an animal frozen and lifeless would lead most to conclude that it died of exposure, having failed to account for weather extremes. The foolish frog theory, which would make a passable subject for Aesop’s fables or a subplot in Disney’s Frozen, is false. Frogs freeze on purpose.

Science entered the picture in the 1980’s when a Minnesota-based researcher with some knowledge of frog adaptability took up the subject. The experiment consisted of collecting a number of frog species in the fall and subjecting them to freezing in the laboratory under controlled conditions. After six days at -6°C, the frozen frogs were moved to a refrigerator and thawed at +6°C. Wood frogs began to show vital signs and limb movement after three days but mink and leopard frogs subjected to the same conditions froze to death and stayed that way. The resulting paper concluded that “an accumulation of glycerol during winter was correlated with frost tolerance, indicating that this compound is associated with natural tolerance to freezing in a vertebrate.” [2] In other words, wood frogs seemed to be making antifreeze. In the four decades that have followed since this seminal experiment, further research has revealed the true nature of the wood frog’s magic.  

What better place to study frozen wood frogs than Alaska where arctic winter is the norm and spring thaw the exception? Researchers located frozen frogs in the wild and measured ambient temperatures with sensors placed directly on their skin. After two seasons with temperatures as low as -18°C and a seven-month long period of deep freeze suspended animation, every wood frog came back to life. [3] That the frogs survived the natural habitat test at much lower temperatures for a much longer time period than in the laboratory test led to some speculation as to the mechanics of freeze protection. Vertebrate metabolism is based on energy generated primarily from the oxidation of glucose derived from dietary carbohydrates. Excess glucose is stored in the liver and in muscle tissue as glycogen for future energy needs. The key to the deep freeze conundrum was that in the laboratory, temperature was lowered to below freezing just once and the frogs froze. In the wild, frogs are subjected to multiple freeze/thaw cycles according to weather fluctuations. It was discovered that each cycle ratcheted up the production of glycogen, ultimately increasing its concentration by a factor of five. To accommodate the stockpile, liver size increased by over fifty percent ― one researcher described the wood frog as a “walking liver.” When compared to wood frogs monitored in more moderate Midwest climates, the Alaskan frogs had three times as much glycogen. [4] While Darwin’s Galapagos finches provided a hint of adaptations for survival, Alaskan wood frogs are a compelling affirmation case study.

The actual mechanism employed not only by wood frogs, but also by spring peepers, gray tree frogs and chorus frogs to revive after freezing to death (heart stoppage and breathing cessation) is now understood to involve both glycerol and glucose in addition to some specialized proteins. Glycerol lowers the freezing point of water to protect membranes from freezing just as it does for automobile cooling systems. Glucose in high concentrations prevents the formation of ice crystals inside cells. Ice crystals are like small daggers, shredding cell membranes and wreaking havoc with organelles. This is why freezing is normally lethal to animals and why frozen vegetables that are not dehydrated turn to mush when defrosted. When a frog senses first frost, adrenaline is released to convert liver glycogen into blood glucose. This is the same mechanism that provides energy for fight or flight (and freeze in frogs). It originates in the amygdala, the brain region that provides for immediate action in emergencies known as the sympathetic nervous system.  The difference with wood frogs is magnitude. Human glucose ranges from 90 to 100 milligrams per deciliter with a diabetic threshold at 200 mg/dl. Frogs boost their glucose to as high as 4,500 mg/dl, well over lethality for humans, and probably for just about every other living thing. The specialized proteins act as ice nucleation sites outside the cells where about 65 percent of total body water ends up frozen. [5] Cryobiology may well be the next frontier in the quest for life everlasting if the lessons learned from wood frogs can be mastered. [6]

The spring thaw fills vernal pools with the cacophony of male wood frogs courting, a behavior known as explosive breeding. As the amphibian exemplar of the early bird gets the worm, the quest for sex begins in early March, even before wet areas are free of ice. Filling the air with their duck-like quacking, male wood frogs frenetically search for something to mate with, not infrequently grasping other males and even other species, including large salamanders. The tenacious grip is called amplexus, aided and abetted by swollen thumbs and expanded foot webbing that won’t let go. [7] It is necessary because females are generally larger than males and slimy frogs are slippery. Mating success of male wood frogs is dependent on physical size,  one of nature’s enduring correlations. It is also true that larger females are more likely to mate as size in this case correlates to the number of eggs produced. After an embrace that can last for over an hour for egg fertilization, the female deposits as many as 3,000 eggs in a gelatinous, globular mass about four inches in diameter. After a time, the ball flattens and collects algae for disguise as pond scum. One month after oviposition, the eggs hatch into aquatic tadpoles for the race against the clock to metamorphose into terrestrial wood frogs before the pool, which may be seasonal, dries up and they expire. Wood frogs can freeze but their young need water. The odds are stacked against survival, but only one tenth of one percent of the eggs in the brood must reach adulthood for survival of the species, at least for those that are fittest. [8]

Amphibians first appeared in the Devonian Era about 400 million years ago as something like a walking fish and have never broken free from their aquatic “roots” even as evolution has run its course. True frogs of the family Ranidae, which don’t appear in the fossil record until 57 million years ago, are long-legged, narrow wasted, and web-footed with horizontal pupils including wood, green and bull frogs. Since their origination occurred after the breakup of the supercontinent Pangaea, global dispersal required continent jumping. DNA assessment of 82 Ranidae species revealed that the North American clade of true frogs came from East Asia, hopping across Beringia and spreading across the New World by 34 million years ago. The first genetic split of the true frogs that spread out in North America was the mutation that became the wood frog, suggesting a significant adaptation. [9] Are wood frogs still evolving? The short answer is yes because everything does, including humans. It is just too slow to notice.

Amphibians are the proverbial “canary in the coal mine” when it comes to planet Earth. They need both clean water because they are aquatic for at least a portion of their life cycle and clean air because we all do. Wood frogs offer a case in point. With climate getting warmer and not colder, ice survival may not have quite the same importance in the future.  One study found that pond temperature had a marked effect on wood frog tadpole development time. Those in colder ponds grew faster. Conversely, warmer water not only slowed tadpole growth but also evaporated more quickly. Rising ambient temperatures will thus reduce the chances for slower growth tadpoles to metamorphose into lunged froglets before the water evaporates due to accelerated desiccation. [10] On the other side of the survival ledger, empirical data from the beginning and end of the last century revealed that temperatures had risen about 3°F and that male wood frogs were calling for mates about two weeks earlier. This would then move conception time up to account for more time needed to gestate and grow. [11] Given their historical evolutionary success over the last 34 million years, it is reasonable to conclude that Rana sylvatica is more likely to survive climate change than Homo sapiens, who have only been around for less than one million.

References:

1. Heinrich, B. Winter  World, Harper-Collins, New York, 2003, pp 169-175

2. Schmid, W. “Survival of Frogs in Low Temperature” Science, 5 February 1982,  Volume 215, Issue 4533  pp. 697-698.

3. Pennisi, E. “How to Freeze and Defrost a Frog”, Science, 8 January 2014.

4. Servick, K. “The Secret of the Frozen Frogs”  Science, 21 August 2013.

5. Heinrich, op cit.

6. Costanzo J et al  “Survival mechanisms of vertebrate ectotherms at subfreezing temperatures: applications in cryomedicine”. The FASEB Journal. 1 March 1995 Volume 9 No. 5 pp 351–358.

7. https://www.nasw.org/users/nbazilchuk/Articles/wdfrog.htm    

8. https://animaldiversity.org/site/accounts/information/Rana_sylvatica.html

9. Yuan, Z. et al. “Spatiotemporal diversification of the true frogs (genus Rana): A historical framework for a widely studied group of model organisms”. Systematic Biology.  Issue 65  No. 5, 10 June 2016  pp 824 – 842.   

10. Renner, R. “Frogs not croaking just yet” Science, 12 My 2004.

11. Wong, K. “Climate Warming Prompts Premature Frog Calls” Scientific American 25 July 2001’

Common Name: Rock Greenshield Lichen – The rosette shape is like a rounded shield and is greenish gray in color ― a green shield found almost exclusively on rocks. Lichen has an obscure etymology but may derive from the Greek word leichein which means “to lick” just as it sounds. There is no extant clue for this association as very few lichens are eaten (and thus licked). Some, like this species, have small lobes that could be a metaphor of sorts for little (leichein) tongues. The Common Greenshield Lichen is found mostly on trees.

Scientific Name: Flavoparmelia baltimorensis – Parmelia is Latin for shield,  the genus that was used broadly for all lichens that were shield shape until 1974 when it was subdivided. Flavo as a prefix means yellow, distinguishing these lichens from the blue tint of other shield lichens… yellow hues combine with blue so that the overall effect is green. This species was first classified from a Baltimore specimen giving rise to the familiar nomenclature.

Potpourri: The rock greenshield lichen and its virtually indistinguishable  cousin the common greenshield lichen (F. caperata) are encountered clinging to a substrate of  rock or wood while traipsing along almost any trail. In the winter months when  deciduous trees are devoid of greenery and mostly annual undergrowth has died back, only the grays and browns of rocks, dirt, leaf litter, and boles remain. The exceptions are the greenshield lichens that spread their leaflike (and tongue-like) lobes outward and onward, oblivious to the reduced light and frigid temperatures by which the rest of the forest is constrained. Their persistence is testimony to the lichen lifestyle, one of the natural world’s wonders. Comprised of a fungus that has partnered  with one or more organisms from a different kingdom, 14,000 identified lichens have mastered the art of survival in the most inhospitable of habitats from hot, dry desert to frozen tundra. They are even found on Mount Everest at elevations exceeding seven kilometers. [1]

According to the International Association of Lichenology, a lichen is “an association of a fungus and a photosynthetic symbiont resulting in a stable vegetative body.” The fungal partner is called the mycobiont and constitutes about 95 percent of the lichen body structure or thallus. Since fungi are heterotrophs and therefore cannot make their own food, they must rely on autotrophs that photosynthesize the sun’s energy to produce nutrients necessary for growth and reproduction. Some fungi consume dead plants as saprotrophs, some parasitize living organisms, and some connect to living plant roots in a mutually beneficial association called mycorrhizal (fungus root). Lichenized fungi evolved a relationship to photosynthesizing organisms that falls into the category of symbiosis, which is defined as an intimate relationship between two living things. The photosynthetic partner of the lichenized fungus is called the photobiont and can be either green, brown, golden algae or cyanobacteria, a type of bacteria that contains chlorophyll formerly called blue-green algae. Algae is now a broad non-technical name for several types of polyphyletic eukaryotes that photosynthesize, which is all that matters to the fungal partner. The photobiont for greenshield lichens is a green alga species in the genus Trebouxia, which is the most common photobiont for all lichens. [2]

The relationship between the fungus and the algae in a lichen is complex. Traditionally the symbiosis of lichens has been characterized as mutualism in which both partners benefit equally. In reality, the relationship frequently ranges from commensalism, where the fungus benefits but the algae do not, to outright parasitism, where the algae are harmed for the benefit of the fungus. Some insight into the living arrangements is afforded by the observation that the lichen’s fungi need the algae but not vice versa. That is to say that none of the lichen forming fungi, comprising almost half of ascomycetes, the largest division of the Fungi Kingdom (mushroom are in the other large division – the basidiomycetes), exist in nature without algae, whereas the algae can and do lead independent lives on their own. However, having a place to live with enough water and air for photosynthesis to make carbohydrates and respiration to oxidize them for energy (both plants and fungi need to breathe) is certainly an algal advantage. It is at the cellular level that the controlling dominance of the fungus can become sinister. The root-like tendrils of the fungus called hyphae surround and penetrate the algal cells, releasing chemicals that weaken the surrounding membrane so that the carbohydrates leak out, feeding the fungus. Weaker algal cells thus violated die, and were it not for periodic reproduction, so too would the lichen. [3] A lichen has been described as a fungus that discovered agriculture, an apt aphorism. The fungus uses the algae for subsistence in like manner to a farmer tending fields to extract their bounty ― it would be nonsensical to assert that farmers and soybeans therefore benefit mutually in symbiosis.

Lichen reproduction is also complicated, as it involves two different species that must reproduce independently and then come into close contact to form a union. While this union must have occurred at least once for any lichen to exist, a singular rare event in the millions of years of geologic time is not unusual. The mycobiont, in this case Flavoparmelia baltimorensis, produces reproductive spores in a fruiting body called an apothecia in a manner analogous to the gills of mushroom fruiting bodies. The photobiont, in this case Trebouxia, also reproduces using spores when it is independent of the fungus, but only reproduces asexually once lichenized. Apothecia are very rarely seen on greenshield lichens, direct evidence that, like most lichens, they have no pressing need for reproductive spores.  Since they are abundantly distributed and can on occasion cover vast swaths of boulder fields (F. baltimorensis) and exposed wood surfaces (F. caperata), it is evident that there is a successful reproductive workaround. In general, this consists of a lichen forming a detachable unit that includes both the fungus and its algal partner for windborne distribution to new locations. These “lichen seed packets” take various forms including soredia that are miniscule balls of fungal hyphae surrounding a few algal cells and schizidia, which are simply flakes of the upper layer of the fungal thallus which also contains the algal layer. One of the ways to tell rock and common greenshield lichens apart is that F. baltimorensis has schizidia and F. caperata has soredia. However, identifying small irregular components on the gnarled surface of a lichen is a challenge even for a lichenologist with a lens. It is much easier to identify a rock or on a tree and look for lichens.

Greenshield lichens often cover broad expanses of rock and tree surfaces to the extent that long term effects come into question. Do lichen covered rocks disintegrate at an accelerated rate? Do trees weaken due to the amount of bark covered by lichens? For the most part, lichens are self sustaining in the sense that the heterotrophic fungus is supplied nutrients from autotrophic algae. While sunlight and water are the essential ingredients for photosynthesis, nitrogen, phosphorous and potassium are also required for plant growth (the three numbers on a fertilizer bag refer to these elements).  It is less well known that fungi need these same nutrients for the same metabolic reasons. [5] In many cases, lichens are able to get all of the nutrients they need from minute amounts dissolved in water. The quality of precipitated rainwater is why lichens are useful for environmental monitoring as their growth correlates to air quality. The two main substrate characteristics associated with lichen growth are moisture retention and exposure to sunlight. For lichens growing on exposed tree bark, the degree to which moisture is retained as it flows down the tree is the key factor. While it is true that the lichen will “rob” some of the nutrients that would otherwise go to the tree roots, the amount is negligible. Deciduous trees have more lichens than conifers because their leafless trunks are sunlit for six months of the year whereas evergreens are ever shaded. Rocks are not good at retaining moisture. Consequently, lichen hyphae penetrate rock surfaces to depths of several millimeters seeking water, and, depending on the type of rock, minerals as well. This contributes to the long-term weathering of rocks for soil formation, and more broadly to the million-year geologic cycle of mountain building and erosion. The answers to the two questions are yes, lichens do disintegrate rocks at a geologic rate, and no, lichens do not harm trees ― they are sometimes called epiphytes for this reason.

Chemistry is another important aspect of lichen physiology. More than 600 unique compounds are concocted by lichens in surprisingly large quantities … up to five percent of total bodyweight. It is instructive to note that when lichenized fungi are artificially grown without algae in a laboratory, chemical output is negligible. This can only mean that specific chemicals promote the associative nature of the individual lichen species.  There are any number of hypotheses that might explain this. Bitterness as deterrence to animal browse is certainly one possibility, as lichens grow quite slowly on exposed surfaces and are easy to spot. However, some lichens, notably reindeer moss (Cladinia rangiferina), are a major food source for animals and are quite likely propagated in their droppings. It is also believed that some chemicals act to coat sections of hyphae to provide air pockets necessary for photosynthesis by the algae. The chemical footprint of a lichen species is one of the main diagnostic tools used in field identification. Lye, bleach and several other reagents are dripped onto the surface; a change in color indicates the presence of a specific chemical that is related to a specific lichen. [4] There are many unknown aspects of lichen physiology. This was made manifest recently when it was discovered that many lichens contain a type of basidiomycete yeast (also a fungus), which is embedded in the body of the ascomycete fungus in varying concentrations that correlate to anatomical differences. Some if not all lichens may actually consist of two fungi and an alga or two, a far cry from simple symbiosis. [6] The function of yeast fungi is not yet known.

The Flavoparmelia genus was separated from the other Parmelia (shield) lichens in 1986 in part due to their production of the chemical compound usnic acid. [7] It is a large molecule with the formula C₁₈H₁₆O₇ which simplifies the recondite but recognized international IUPAC standard 2,6-Diacetyl-7,9-dihydroxy-8,9b-dimethyldibenzo[b,d]furan-1,3(2H,9bH)-dione. Usnic acid is found primarily in the top layer of the fungus along with another chemical called altranorin just above the area where the algal bodies are concentrated. It is surmised that they contribute to shielding green algae from excessive sunlight exposure since bright sun is inimical to photosynthesis, the source of all lichen energy. Usnic acid is also a potent antibiotic, collected primarily from Usnea or beard lichens due to higher concentration for use as an additive in commercial creams and ointments. Flavoparmelia caperata is one of several lichens that have historically been used by indigenous peoples as a tonic taken internally or as a poultice applied to a wound. [8] The medicinal uses of lichen fungi should come as no surprise, as many polypore type fungi growing as brackets on tree trunks have been used medicinally for millennia. The abundance of rock and common greenshield lichens is evidence of successful adaptation. In addition to thriving on bountiful rock and wood surfaces, the chemical shield screens sunlight to protect the green algal energy source and guard against assault by microbes and mammals.  In other words, they are literally green shields.  

Carl Linnaeus assigned lichens to the class Cryptogamia meaning “secret life” along with everything else that created spores and not seeds. [9]  One of the more enduring lichen secrets is how and when the coalition between fungi and algae began. It is widely accepted that simple replicating organisms started out in aqueous habitats, as water affords bodily support and nutrient transport. The transition from sea to shore would have been nearly impossible for an alga with no structure or a fungus with no food. There is good reason to suppose that some form of union like a lichen may have come about by chance and was then promoted by survival.  Scientific research over the last several decades has cast some light into the dark shadows of this distant past. What look like lichen hyphae embedded in the soil around fossils from the pre-Cambrian or Ediacaran Period (635-541 million years ago) suggest that lichens may have been the first pioneers on dry land. [10] This is supported by the finding that marine sediments from this same period contain not only the root-like hyphae of fungi but also the rounded shapes of blue green algae or cyanobacteria. This suggests that something lichen-like started out in the water was left high and dry in a tidal flat to make the critical transition. [11] However, recent DNA analysis of primitive ferns and lichenized fungi revealed that the lichens evolved 100 million years after vascular plants.[12]  Lichenology, like all science, is a continuum that never ceases in its quest for knowledge. Future field tests and experiments are certain to clarify the origin story.

References: 

1. Kendrick, B. The Fifth Kingdom, 3^rd edition, Focus Publishing, Newburyport, Massachusetts, 2000, pp 118-125.

2. Brodo, I., Sharnoff, Steven and Sylvia. Lichens of North America Yale University Press, New Haven, Connecticut, 2001. pp 1-112, 316-317, 479-484.

3. Wilson, C. and Loomis, W. Botany, 4^th edition, Holt, Rinehart, and Winston, New York, 1967, pp 451-453.

4. Brodo, op. cit.

5. Kendrick, op. cit. pp 142-158.

6. Spribille, T. et al “Basidiomycete yeasts in the cortex of ascomycete macrolichens” Science Volume 353 Issue 6298, 21 July 2016, pp 488-492.

7. Hale, M.  1986. “Flavoparmelia, a new genus in the lichen family Parmeliaceae (Ascomycotina)”. Mycotaxon. 25 (2): April-June 1986.pp 603–605

8. Brodo, op. cit.

9. Linnaeus, C. Species Plantarum. Vol. 2. Stockholm: Impensis Laurentii Salvii.1753. p. 1142

10. Frasier, J. “Were Weirdo Ediacarans Really Lichens, Fungi, and Slime Molds?” Scientific American 13 December 2012.

11. Yuan, X. et al “Lichen-Like Symbiosis 600 Million Years Ago” Science  Volume 308, Issue 5724, 13 May 2005, pp 1017-1020

12. Frederick, E. “Hardy lichens don’t actually predate plants” Science 20 November 2019