Perennial herb to 1 m tall Stem: single or multiple from base, upright, hollow, unbranched, bristly-hairy. Leaves: opposite, stalkless, 8 - 18 cm long, 2 - 6 cm wide, lance-shaped to egg-shaped with base narrowing below middle, coarse and hairy above, less hairy beneath. Flowers: usually solitary in leaf axil. Sepals five, 9 - 12 mm long, linear, elongate, bristly along the margins. Corolla unequally five-lobed, greenish yellow, about 2 cm long, tubular or bell-shaped, base swollen, loosely hairy. Stamens five. Anthers yellow. Fruit: berry-like (drupe), orangish red, dry. There are three oblong stones inside each drupe.
Similar species: In the Chicago Region, Triosteum angustifolium differs from other Triosteum species by having bristly-hairy stems and hairless sepals with bristly margins.
Flowering: April to May
Habitat and ecology: Moist woods and low ground. Rare in the Chicago Region.
Occurence in the Chicago region: non-native
Etymology: Triosteum comes from the Greek words treis, meaning three, and osteon, meaning "a bone" (in reference to the three stones inside the fruit). Angustifolium means "narrow leaved."
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
This species is undoubtedly restricted to the southern half of the state. I have found it on dry, wooded slopes only, and usually associated with black and white oak.
More slender than the previous 2 spp., the stems 3-8 dm, sparsely and retrorsely setose-hispid with hairs 1.5-3 mm and also glandular with shorter hairs; lvs oblanceolate to obovate, the main ones 8-18 נ2-6 cm, narrowed below the middle to a sessile base, setose-strigose above with hairs 1-2 mm; fls usually solitary in the axils; sep 9-12 mm, hispid-ciliate, the back glabrous or pubescent; cor greenish-yellow, loosely villous; fr orange-red. Moist woods and low ground; May, June. Two vars.: Var. angustifolium, pubescence of the lower lf-surface none or restricted to the veins; lvs mostly about a fourth as wide as long; Conn. to s. Ont., O. and Mo., s. to N.C., Ala., and La. Var. eamesii Wiegand, lvs softly pubescent over the surface beneath, often obovate, ca half as wide as long; Conn. to N.J. and N.C.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.