Fly Poison


The various common names of this ubiquitous and prolific spring flower attest to its substantive toxic properties

Common Name: Fly Poison, Stagger grass, Crow poison – The high toxicity of the plant to fauna is reflected in its baneful name.

Scientific Name: Amianthium muscaetoxicum – The Greek word for pure is amiantos which, when coupled with the word for flower, anthos produces the generic name ‘pure flower.’ This is alleged to indicate that the flower, unlike most other lilies, lacks nectar producing glands (nectaries) at the base of the tepals. The specific name is literally Latin for fly poison (musca toxicum). It is alternatively listed as Chrosperma muscaetoxicum in some older texts and it is also frequently found in the genus Zigadenus. The generic confusion is somewhat perplexing, as the plant is a monotype – it is the only species in the genus.

Potpourri: The various common names of this ubiquitous and prolific spring flower attest to its substantive toxic properties that were well known to the Native American population that preceded European colonization. The Cherokee used the plant both as a medicinal and as a toxin; the root was ground to make a poultice for application to treat severe itching and alternatively mixed into an otherwise attractive morsel as a means to poison crows. It is implicit in this application that the Cherokee sought to exterminate the persistent corvine marauders that would otherwise vandalize their cornfields – the same rationale that motivated the later use of the scarecrow. The Indian herbalism was adopted by the European colonists who parlayed the toxic plant into a potent means to eradicate the ubiquitous flies, resulting in the widely used name ‘fly poison’ as a mnemonic descriptor. The sobriquet ‘stagger grass’ was also coined by the colonists to describe the effects that ingestion of A. muscaetoxicum had on the herd animals that they introduced to the cleared woodlands of the early settlements.

The various alkaloid substances produced by the plant are neurotoxic to cattle, sheep, goats and probably a lot of other things. The primary toxins of concern are jervine and amianthine, the latter named for the genus of the plant. Of the two, jervine is the most well-known, as it is also found in plants of the genus Veratrum, like the false hellebore (Veratrum album) a plant found in similar habitats. Jervine is a potent teratogen, i. e. it induces serious birth defects in the young of mammals that ingest it. A 1912 citation in the Journal of Pharmacology and Experimental Therapeutics noted that “The alkaloid is of extreme toxicity, producing death from respiratory paralysis.” The initial symptoms of ‘fly poisoning’ consist of excessive salivation and digestive distress which are succeeded several hours later by muscular weakness that manifests as a staggered gait accompanied by respiratory distress. The symptoms generally persist for several days as the toxic substances are purged and excreted. However, if relatively large quantities (on the order of 0.3% of body weight – about 1 pound of vegetative matter for a 300 pound cow) are eaten, death by respiratory failure results. There are no known antidotes to the poison; the veterinary regimen consists of a combination of sedatives to induce passivity and palliatives to reduce gastric reactivity.

Grazing animals will generally shun poisonous plants as the inherent bitterness of the alkaloid toxins will minimize their exposure in favor of greener pastures. However, when there is a dearth of alternative fodder vegetation for the grazer, the likelihood of toxic plant consumption increases. This is exacerbated by the benign appearance of the immature plant, a veritable tuft of proffered nutrition. A 1913 citation in the U. S. Department of Agriculture Farmer’s Bulletin enjoined farmers to “recognize this fact and take a few obvious precautions,” such as: don’t let your animals graze on the range when there is nothing to graze on; and to keep animals away from poisonous plants. Special precautions are enjoined when animals are in transit from one location to another over commonly used trails, as most of the good fodder would have been consumed, leaving only the poisonous leftovers. In addition to stagger grass, the Bulletin also warns against milkweed, larkspur, wild cherry, and water hemlock or cicuta.