Monographs Details: Triosteum angustifolium L.
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Species Description - 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 × 2–6 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.

Common Names:lesser horse-gentian