Perennial herb 30 cm - 1 m tall Stem: single or clustered, erect, very leafy, and more or less hairy. Leaves: many, alternate, short-stalked, usually somewhat hairy, mostly non-toothed, 7 - 16 cm long, over 3 cm wide, broadly elliptic to oblong with tapered base and abruptly narrowed, elongate, pointed tip. Flowers: inconspicuous (4 - 5 mm long), light green to white or pale yellow-green, somewhat bell-shaped but bilaterally symmetric, and hanging on curved stalks in leaf axils (one to several per axil). The flower stalk is obviously jointed beyond the middle, just before the downward curving portion. Sepals: five, linear, nearly as long as petals, and usually persisting in fruit. Petals: five, separate but not spreading, greenish, notched with tips flaring outward, and lowest petal larger and more strongly notched than others (appearing almost two lobed) with the base swollen into a short nectar sac. Stamens: five, but united into a sheath surrounding the pistil and bearing a two-lobed gland at the base on the lower side. Pistil: with a single-chambered, three-valved, superior ovary; and a single, elongate, hook-shaped style ending in a single expanded stigma. Fruit: a narrowly oblong to ellipsoid, 1.5 - 2 cm long capsule that opens by three lengthwise valves, each valve with seeds attached lengthwise down the center. Seeds: many, 5 mm in diameter, rounded almost globular, and with large amounts of oily endosperm.
Similar species: The only species of Hybanthus in eastern North America, H. concolor is probably most similar to H. verticillatus, which occurs in the southwestern United States. That species differs by being smaller overall, having narrower (well under 1 cm wide) leaves that may sometimes be opposite or whorled. The closely related members of the genus Viola are easily distinguished since most species do not have such erect and tall stems (rarely over 25 cm), there are much fewer leaves (usually only up to eight), and the flowers are more conspicuous and unmistakably bilaterally symmetric.
Flowering: April to May
Habitat and ecology: Uncommon, localized to mesic woods.
Occurence in the Chicago region: native
Notes: This genus is mostly a tropical or at least warm climate genus, with this being the only species in eastern North America.
Stems to 1 m, solitary or clustered, from a crown of fibrous roots; herbage ±hairy; lvs broadly elliptic to ovate-oblong, 7-16 cm, abruptly acuminate, tapering to slender petioles 1-2 cm; fls greenish-white, 4-5 mm, solitary or several in the axils on strongly recurved peduncles jointed beyond the middle; sep linear, nearly as long as the pet; fr oblong-ellipsoid, 1.5-2 cm; seeds subglobose, 5 mm; 2n=48. Rich woods and ravines; Vt. and Ont. to Mich. and Kans., s. to N.C., Ga., and Ark. May, June. (Cubelium c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.