Barberry, Japanese



The bright red berries of the barberry attract birds which contributes to its spread


Common Name: Japanese Barberry, Barberry, Berberry, Thunberg’s barberry, Red barberry– The common name is an Anglicized form of the genus Berberis to which the plant is taxonomically assigned.


Scientific Name:  Berberis thunbergii – The generic name is Arabic for shell (برباريس) which is thought to refer to the fact that the leaves have a shiny gloss that is reminiscent of the nacreous luster of an oyster shell. The species name honors Carl Thunberg, a Swedish naturalist and student of Carolus Linnaeus who is noted for the description of many Japanese and South African species. 


Potpourri: The barberries of the genus Berberis are distributed globally with more than 400 individual species. Primarily of Asian, African and South American provenance, they are characterized by prominent thorns that project perpendicular to the stems of the shrubby, largely evergreen plants. In North America, there is an American barberry, B. canadensis that is indigenous, a European barberry, B. vulgaris, that was introduced, and an Asian barberry called Japanese barberry, B. thunbergii that is invasive. They all have red berries, prominent thorns and ovate to obovate leaves growing in bushes that can be up to three meters in height though generally shorter. The thorns that protrude at the base of the leaves are a good field identifier of the genus; the only other red-berried shrubby tree with similar thorns is the aptly named hawthorn. The notoriety of the barberry in Europe and its attendant protuberant thorns earned it the sobriquet “holy thorn” in Italy; the attribution referring to European barberry as the source for the crown of thorns placed on the head of Jesus in the final transit to Calgary.

The invasive Japanese barberry has become a persistent pest throughout the region

The invasive and weedy Japanese barberry (B. thunbergii) is the variety that is encountered growing along the trail in open, well-lit spaces. The plant was intentionally introduced as an exotic ornamental plant in 1875 at the Arnold Arboretum in Boston, Massachusetts; the seeds having been procured in Russia. Twenty years later, the resultant shrubs were transplanted at the New York Botanical Garden; by the turn of the century, the Japanese barberry had become naturalized. Over the course of the last century, more than forty cultivars have been developed by horticulturalists for sale as garden plants for landscaping purposes. They are highly regarded for their attributes: perennial attractive glossy leaves that are shunned by browsing deer; hardiness in marginal soil environments; a tendency to spread in the form of barrier hedges of impenetrable thorniness; and the production of copious berries that attract a wide assortment of birds. The downside is that the Japanese barberry is too successful, crowding out indigenous native plants. It grows vegetatively and can expand outward from a single plant to a cloned copse; each plant produces a prodigious number of seeds – over four thousand per plant for some cultivars. Many birds eat the seed bearing berries, providing the vector for dissemination with a nutritive dollop of natural fertilizer.  The seeds have a germination rate of about 90 percent, so that almost all succeed to seedlings. In the absence of native arthropod or mammal consumption, the Japanese barberry has spread and has thus become invasive and something of a nuisance.

The European barberry (B. vulgaris) was also intentionally introduced, but for different reasons and with profound consequence. The barberry has been a staple of Old World apothecaries for several millennia. The ancient Egyptians employed an admixture of barberry and fennel to ward off the ravages of plague; the traditional ayurvedic healers of India used it to treat dysentery; the Chinese have used it for a wide variety of ailments for over 3,000 years. By the middle ages, it had been adopted by the early European herbalists for liver and gall bladder disorders among many other applications. The berries were also widely used to make preserves for use as a spread or a garnish for meat.  The extent to which barberry was commonly used in England is best expressed in the writings of Nicholas Culpepper in his Complete Herbal of 1653 “The shrub is well known to every boy and girl that has but obtained to the age of seven years, that it needs no description. Mars owns the shrub, and presents it to the use of my countrymen to purge their bodies on choler. The berries are as good as the bark … they get a man good stomach to his victuals.”  When the English colonists came to the New World, they brought their beloved barberry with them, unaware that there was a North American species, B. canadensis, with essentially the same medicinal and gustatory attributes. They also brought wheat to produce the essential daily bread of their culture, thus perpetuating one of the most complex fungal interactions that has had devastating consequence to the global food supply; it is still a major problem in famine-prone sub-Saharan Africa.

Black stem rust (Puccinia graminis) of wheat has been a recognized problem among European agronomists since the first notations in the historical records of ancient Greece. The Roman pantheon included Robigus, the god of rust, whose annual festival of Robigalia was held on the 25th of April. The ceremonies consisted of the sacrifice of an animal with red fur, usually a dog, to propitiate the god and ward off the scourge of the red rust fungus and its attendant famine. Over centuries of empirical observation, it became manifest that there was a more than serendipitous correlation between an infestation of wheat with the rust fungus and the presence of barberry to the extent that the latter was banned in the French city of Rouen in 1660. The wheat rust/barberry problem spread to North America with the colonists such that the same prohibitions against barberry were instituted by Connecticut in 1724 followed by Massachusetts in 1754.

Comprehension of the heteroecious or two-host nature of P. graminis was not fully explained until 1865 when Heinrich Anton de Bary, a German botanist who is considered the father of modern mycology deciphered the complex life cycle. The full fungal infestation sequence between the two hosts was not settled until 1927 by John Craigie, a Canadian plant pathologist. When an airborne spore germinates on a wheat plant, the fungal mycelium spreads over the individual grains (which render them inedible), producing more spores which can infect other wheat plants during the growing season. This can extend from one field to another until the entire regional crop is infested.  At the end of the season the fungus produces a second type of spore that does not infect the wheat, but requires the barberry as an alternate host. When the wind blown spores germinate on the leaves, they spread out in hyphae to form a mycelium that produces two compatible mating types (fungi do not have sexes per se). The sexual union on the barberry leaf produces yet another type of spore that completes the cycle – i.e. it germinates on wheat grain where its immediate host barberry is immune. The colocation of barberry and wheat greatly facilitates the transport of the spores and the concomitant spread of the fungus. Conversely, if the barberry can be eradicated, then the fungus cannot reproduce as its life cycle is blocked.  

After a particularly bad rust epidemic in the wheat-growing Great Plains region in 1916, laws proscribing the growth of barberry were enacted in the Dakotas in 1917 and in the upper Midwest in 1918. The loss of wheat due to rust damage in the five years between 1917 and 1922 was 143 million bushels. Due to the substantial economic loss and the interstate nature of the problem, a comprehensive federal program to eradication barberry was established by the USDA in 1918. Over the next two decades, over 120,354 properties in 17 states were cleared of almost 300 million barberry plants. Similarly, Canada passed a federal law banning barberry in 1919. The success of these efforts has essentially eliminated the problem of rust epidemics in western North America; the last major outbreak in the United States was in 1962. However, there has been one unintended result, the native barberry B. canadensis, which is not involved in the life cycle of wheat rust, was also largely exterminated. It is listed by the USDA as endangered in Illinois, Indiana and Kentucky, and extirpated in Maryland and Pennsylvania. It should also be noted that the Japanese barberry, B. thunbergii, is also not involved in the life cycle of wheat rust. Wheat rust is still a problem in the United States, as there are other hosts besides European barberry; however, they are dealt with locally with fungicides. Wheat rust is also a global problem, the most recent outbreak was in Uganda in 1999, and the toponymic Ug99 strain of wheat rust is spreading throughout Africa with fears of an Asian pandemic. The global effort to rid the wheat fields of the troublesome fungus is in statu nascendi.

It is truly a pity that European barberry and its harmless American cousin have been essentially wiped out in North America, as they are of exceptional merit in the treatment of a variety of ailments, to say nothing of the use of barberry in the manufacture of yellow dye by both Native American “Indians” and Asian (real) Indians. The primary active ingredient is Berberine, a derivative of the genus Berberis. The Peterson Field Guide to Medicinal Plants and Herbs provides that “Berry tea used to promote appetite (recall Culpeper’s admonition to get a man good stomach to his victuals), diuretic, expectorant, laxative; also relieves itching. Root bark tea promotes sweating, astringent, antiseptic, blood purifier; used for jaundice, hepatitis (stimulates bile production), fevers, hemorrhage, diarrhea. Leaf tea used for coughs. Root bark tincture used for arthritis, rheumatism, sciatica. Contains Berberine, which has a wide spectrum of biological activity, including antibacterial activity; useful against infection. Contains berbamine, which increases white blood cell and platelet counts.” However, this seeming wonder drug is afforded the caveat “large doses harmful,” without any indication of what constitutes large. It is available as a supplement in a variety of sizes, doses, and prices in most nutrition stores, and, of course on-line. As bread is one of the primary staples of western civilization, the sacrifice of barberry to minimize the growth of the debilitating wheat rust fungus has some appeal from both a practical and philosophical perspective. And, since you can obtain the medicinal benefits of Berberine in pill form, it is possible to have your bread and eat it too.