Plants annual, from somewhat succulent roots. Stems 1-several, initially erect, often becoming prostrate or ascending, usually 1.5-3 dm. Leaves compound; blade with 2 orders of leaflets and lobes; ultimate lobes elliptic, variable in size, margins incised, apex subapiculate. Inflorescences racemose, commonly 6-10-flowered, equaling or barely exceeding leaves, sometimes poorly developed, cleistogamous-flowered racemes present, inconspicuous, 1-5-flowered; bracts elliptic, 6-12 × 3-7 mm, proximal bracts often leaflike or variously incised, distal reduced and entire. Flowers erect; pedicel slender, 6-15 mm or more; sepals lanceolate, ca. 1 mm; petals pale yellow, spurred petal 7-9 mm, spur incurved, ca. 2 mm, crest high, marginal wing well developed, both crest and wing wrinkled or dentate, unspurred outer petal similar to spurred petal, 6-8 mm; inner petals 5-7 mm, blade apex ca. 2 times wider than distinctly lobed base, claw 2-3 mm; nectariferous spur less than 1/2 length of petal spur; style 1.5-2 mm; stigma wider than long, with 4 terminal papillae. Capsules pendent, linear, straight or sometimes reflexed, (14-)18-20(-22) mm. Seeds ca. 2 mm diam., minutely decorated on narrow marginal ring. Flowering early-late spring. Wooded slopes, bottomlands, and rock outcrops, in moist, loose soil; 0-650 m; Ont.; Ala., Ark., Del., D.C., Fla., Ill., Ind., Iowa, Kans., Ky., La., Md., Mich., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Va., W.Va.
Green or glaucous annual 1-3 dm, at first erect, often becoming prostrate, the stem sympodial; racemes barely if at all exceeding the lvs; bracts ovate, foliaceous, 3-8 mm; cor pale yellow, 7-9 mm, incl. the 1-2 mm spur; crest of the upper pet usually toothed; frs spreading or drooping, 1.5-2 cm, on pedicels commonly (0.5-)1-1.5 cm; fls sometimes cleistogamous; seeds ca 2 mm wide, with a narrow, acute ring-margin; 2n=16. Moist soil; e. N.Y. to s. Ont., s. Mich. and S.D., s. to N.C., La., and Okla. Apr., May.
The Asian C. ophiocarpa Hook.f. & T. Thompson sometimes escapes from cult.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.