Shrub or small tree; lvs long-petioled; lfls sessile, ovate or elliptic to rhombic or ovate-oblong, the lateral ones oblique; cymes 4-8 cm wide; pet oblong, pubescent, 4-7 mm; filaments pubescent; fr 15-25 mm wide, reticulate-veiny, with the odor of hops; 2n=42. Moist or rich woods and thickets; widespread in Mex. and sw. U.S., n. and e. to Kans., s. Wis., s. Mich., O., N.C., and Fla., and irregularly to s. Que., Vt., w. N.Y., N.J., and Va. May, June. Our plants all belong to ssp. trifoliata, most of them to the glabrous or inconspicuously pubescent var. trifoliata. The mainly more southern var. mollis Torr. & A. Gray, with the lvs and twigs evidently pubescent, the lvs densely so beneath, extends n. into our range as far as D.C. and is disjunct on sand-dunes along the s. shore of Lake Michigan, where it has been called var. deamiana.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Martin and Hutchins 1980, Kearney and Peebles 1969, Wiggins 1964, Correll and Johnston 1970, Carter 2012, Allred and Ivey 2012
Common Name: common hoptree Duration: Perennial Nativity: Native Lifeform: Tree Wetland Status: UPL General: Strongly-scented deciduous shrubs or small trees reaching 6 m tall; bark smooth brownish-gray. Leaves: Alternate (occasionally opposite) along the stems, on long petioles; blades palmately compound with three sessile, elliptical leaflets; each leaflet 1-10 cm long and 3-50 mm wide, with a pointed tip; leaflet surfaces yellowish-green to blue green and shiny above, paler and hairy below. Flowers: Greenish-white and somewhat showy, in cymose clusters with stalks shorter than the leaf petioles so that the flower clusters are buried in the leaves; unisexual and bisexual flowers are found on the same plant; sepals 4 or 5 per flower, united at the base; petals 4 or 5 per flower, about 5 mm long, white to greenish. Fruits: Samara (dry, winged fruit) 1-2 cm long, flattened, nearly circular, with a thin wing all around. Ecology: Found in canyons, on shady and open slopes from 3,500-9,000 ft (1067-2743 m); flowers May-June. Notes: This is a large shrub with leaves in 3's; whitish flowers that resemble orange blossoms (they are in the same family); and dry, winged fruits similar to ash or maple fruits but flat and round. When the leaves are held up to the light, you will notice many delicate punctations or tiny glands on the surface. Crush the leaves to release a strong citrus-y scent. Can be confused with velvet ash (Fraxinus velutina) because of the 3-foliate leaves, but that species lacks the scented glands and has opposite leaves (look at where each set of 3 leaflets attaches to the branch). P. trifoliata is a quite variable species. Numerous subspecies and varieties have been proposed to describe the variation, but they are difficult to distinguish and are not necessarily worth worrying about. Ethnobotany: Root used as a seasoning and as a sacred medicine that holds many cures and that makes other medicines potent; leaves used externally for stomachaches, and also made into a poison. Etymology: Ptelea is the Greek name for elm, used because the fruits are similar; trifoliata means three-leaved. Synonyms: None Editor: SBuckley 2010, AHazelton 2017