Hop tree (Ptelea trifoliata)

Features and Characteristics

Ptelea trifoliata, commonly called hop tree, is a dense, rounded, Missouri native, deciduous shrub or small tree which occurs in open woods, glades, ravines, thickets and prairies. Typically grows to 10-20′ tall. Features compound, trifoliate, shiny, dark green leaves (each leaflet is 2-5″ long) which turn greenish yellow in autumn. Terminal clusters (cymes) of tiny white flowers appear in late spring, but are not particularly showy. Carrion flies pollinate the flowers. Flowers give way to pendulous seed clusters, each seed being encased in a thin, circular, winged disc (1″ diameter samara). Seeds mature to brown in late summer and persist through most of the winter. This tree has several very descriptive common names: (a) hop tree (in reference to a prior use of the seeds as a substitute for hops), (b) wafer ash (in reference to the thin, wafer-like appearance of the seed and (c) stinking ash (in reference to the unpleasant smell of not only the flowers but also bruised foliage and bark).

Genus name comes from the Greek name ptelea for an elm tree for its flattened, almost circular fruit which have a wing all around like that of an elm.

Specific epithet means with three leaves or leaflets.