This small tree is the New World’s northernmost member of the Rue (citrus) family. Once widely used for medicine, it’s too small for lumber and is useful only to wildlife and landscapers. But it’s very distinctive and interesting.
The Common Hoptree’s compound leaves have alternately-arranged leaves with three leaflets, hence the Latin species name, P. trifoliata. The compound leaves resemble ash leaves, but with fewer leaflets, which together with the wafer seeds (samaras), explain another common name, Wafer Ash. The leaves have small oil glands which produce a distinct odor when crushed, and explain still another common name, Stinking Ash.
The Hoptree is generally less than 20′ high, with a trunk up to 10 inches in diameter, and smooth, gray bark which emits a disagreeable odor when crushed. The fruits consist of round samaras similar to elm seeds, but with two or three seeds per wafer instead of one. The yellow-green samaras stand out against the dark green leaves in summer and have a distinctive citrusy taste resembling beer hops, from which it derives its common name. The Hoptree is usually dioecious, i.e., it has female flowers (and fruits) on some trees, and male flowers on others. However, Hoptrees occasionally have “perfect flowers”, which have both male and female parts. Notice that some sources regard the Hoptree as primarily monoecious, with dioecious variants. The compound leaves of three leaflets resemble the American Bladdernut, but the latter’s leaves are oppositely arranged, and it produces three-sided papery bladder fruits.
Hoptree wood is heavy, hard, and close-grained, with a density of 0.83 g/cc), according to Harriet L. Keeler’s Our Native Trees and How to Identify Them. No information was available on its measured hardness, but its density, which closely correlates with hardness, is on par with that of persimmon, Ohio’s hardest native commercially-available wood.
Common Hoptree is a popular landscaping tree in Europe, but it gets a little attention stateside. It grows well in sunny, well-drained areas. The Common Hoptree it’s not at all common in my experience, but you can see a number of them near the Indian mound at Franklin County’s Battelle-Darby Metro park. I’ve also seen many of them along a Rails-To-Trails path near Urbana Ohio. Those at Battelle-Darby were crowded and shrub-like, while the ones near Urbana grew in open sun with tree-like growth.
Hoptree’s bitter fruit was often used as a substitute for hops in beer making. Bark from the roots was used extensively for folk medicine. According to Laura C. Martin’s The Folklore of Trees and Shrubs, “its reputation as a powerful general tonic was surpassed only by goldenseal. Extracts from the plant were often used to strengthen or intensify the effects of other medicines in treating asthma, fever, and digestive disorders.” The North American Ethnobotany Database http://naeb.brit.org/uses/search/?string=Hoptree indicates that Native Americans used Hoptree root bark for various medicines and to increase the potency of other medicines. The Meskwaki used it to treat lung ailments and the Havasupai rubbed on children’s bellies to relieve stomach aches. The Havasupai also mixed Hoptree root bark with hallucinogenic Jimson Weed (Datura), scorpions, and other noxious substances to make a dip for poison arrows.
I’d be happy to plant Common Hoptree in my back yard, but its wetness makes Bladdernut a better bet. I guess I’ll just have to buy my beer.