Leaf blade usually 1-pinnate, distalmost leaf occasionally simple; leaflets usually unlobed, occasionally some 1-2-lobed, mostly 4-11 × 1.5-6 cm (occasionally smaller in w part of range), thin. Flowers: sepals mostly 1-3(-3.5) cm; stamens with filaments and extended connectives pubescent, occasionally glabrous. 2 n = 16. Flowering spring-fall (Mar-Oct). Limestone outcrops in dry to moist woods and thickets, disturbed sites; 0-2200 m; Ark., Ill., Ind., Iowa, Kans., Ky., Mo., Nebr., N.Mex., Okla., Tenn., Tex.; Mexico.