Annual, glabrous throughout; stems and leaves glaucous (bluish); stems 3-6 dm tall, simple below, branched from about 1 dm upward; leaves somewhat fleshy, greenish and minutely punctate above, slate-colored and nonpunctate below; lower stem leaves sessile, auriculate, lyrately pinnatifid to nearly runcinate, 8-12 cm long, 2-4 cm wide; leaves gradually reduced upward; upper stem leaves mostly entire, occasionally sinuate-dentate, ovate to broadly oblong, obtuse, auriculate and clasping the stem; inflorescence racemose, usually fewer than 10 flowers per raceme; flowers slightly zygomorphic; sepals straw-colored to pale purplish, not swollen, narrowly ovate, 9-11 mm long, about 2 mm wide, lateral sepals more narrowly tapered and thicker at tip than upper and lower sepals; petals showy, purplish, 15-18 mm long, blades 3-5 mm wide, reflexed at flowering; stamens 4, upper pair protruding beyond sepals, filaments 7-9 mm long, anthers 2.5-3 mm long, lower pair of stamens with anthers included, filaments 4-5 mm long, anthers 3-4 mm long, single stamens often with anthers longer than filaments; fruiting pedicels stout, terete, divaricately ascending, 5-10 mm long, strongly expanded at the summit; siliques subsessile, divaricately ascending, linear, obtuse to somewhat acute above and below, strongly flattened parallel to the plane of the septum, 4-7 cm long, 5-7 mm wide, valves with a central nerve from base to apex, septum translucent, entire, funicles winged; seeds flattened, widely wing-margined, orbicular, about 5 mm in diameter, wings uniform, 1-1.2 mm wide. Flowers May through June.