Annual to 1.5 m; stipules and stipellules ovate or lanceolate, striate; lfls 2-8 cm, ovate or rhombic-ovate, broadly rounded at base; infls peduncled from many of the axils, with broadly obtuse to subtruncate bracts and 2-many pale purple to whitish fls 12-18 mm; cal-lobes 1-2 mm; frs 1.5-4 cm, strigose at least on the sutures; 2n=20. Highly variable especially in pubescence, but scarcely divisible into vars. Abundant in woods and thickets; Que. and N.S. to Man. and Mont., s. to Fla. and Tex. Aug., Sept. (A. monoica; A. pitcheri)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Usually frequent in moist woods throughout the state. Our two species seem to intergrade and some authors regard the next one [A. bracteata var. comosa] as only a race or vigorous form of this species. Schively expresses this doubt when she says the var. comosa is "an extremely vigorous" form of this species (Contr. Bot. Lab. Univ. Pa. 1: 356. 1897). Besides the winter pods, this species has subterranean 1-seeded pods, autumnal 1-seeded pods, and pods, which are usually 3-seeded, from petaliferous flowers. [Amphicarpaea bracteata var. comosa, if recognized, is] infrequent to frequent in moist woods throughout the state and sometimes in prairies. This species much resembles the preceding [Amphicarpaea bracteata] but, besides the characters given in the key to distinguish it, the plant is larger and coarser, and the leaflets especially are thicker and larger.