Biorepository Data Portal

Annuals; with a fine taproot; ± densely pubescent, trichomes several-rayed, rays distinct or fused at base, bifurcate, (prominently tuberculate throughout). Stems simple or few to several from base, erect, (sometimes branched), to 4 dm. Basal leaves: blade elliptic to rhombic, 3-8 cm, (base narrowing gradually to petiole), margins entire, repand, coarsely toothed, or pinnatifid. Cauline leaves: (proximal often shortly petiolate, distal sessile); blade linear or narrowly obovate, 1.5-6(-10) cm, margins entire, repand, or shallowly toothed. Racemes usually loose. Fruiting pedicels (usually divaricate, sometimes horizontal, straight or slightly curved), 8-20 mm. Flowers: sepals elliptic or ovate, 4-6 mm, (lateral pair usually subsaccate); petals obovate to obdeltate, 6-10 mm, (apex often emarginate). Fruits not didymous, ± globose, slightly inflated, 4-6 mm; valves (not retaining seeds after dehiscence), glabrous throughout; replum as wide as or wider than fruit; ovules 4 per ovary; style 2-3.5 mm; (stigma expanded). Seeds flattened, (margined). 2n = 10. Flowering Apr(-May). Shallow limestone-derived soils, sometimes spreading to disturbed sites; 90-300 m; Okla., Tex.