52. Physaria mcvaughiana (Rollins) O’Kane & Al-Shehbaz, Novon. 12: 325. 2002.
Lesquerella mcvaughiana Rollins, Contr. Gray Herb. 171: 44. 1950
Perennials; caudex simple or branched, (sometimes enlarged); densely pubescent, trichomes (sessile), several-rayed, rays fused (webbed) most of their length, (umbonate, peltate, tuberculate throughout). Stems few to several from base, erect or outer ones decumbent, 0.5-4 dm. Basal leaves (long-petiolate); blade elliptic to obovate or rhombic, 2-6(-9) cm, margins entire. Cauline leaves (sessile or shortly petiolate); blade oblanceolate to spatulate, 1-3 cm, (proximal broader), margins entire. Racemes dense, (relatively short). Fruiting pedicels (erect to spreading, ascending, or (proximal) horizontal, straight to slightly curved, sometimes loosely sigmoid), 6-12(-20) mm. Flowers: sepals elliptic or narrowly oblong, 4-5.4 mm, (tapered to apex); petals (white, base and claw yellow, conspicuously purple-veined), usually broadly obovate or rhombic, 6-10 mm, (± equal to blade, tapering to slender claw). Fruits (sessile or substipitate, often reddish magenta), usually ovoid to subglobose, inflated, 4-6(-7) mm; valves (not retaining seeds after dehiscence), glabrous; replum as wide as or wider than fruit; septum perforate; ovules 8-12 per ovary; style 1.5-4 mm. Seeds somewhat flattened. 2n = 12.
Flowering mid Mar-Apr(-Aug). Stream bed gravels, rocky limestone slopes and hills, canyon bottoms and slopes, limestone rubble; 1200-1600 m; Tex.; Mexico (Coahuila).