4. Erysimum capitatum (Douglas ex Hooker) Greene, Fl. Francisc. 269. 1891.
Cheiranthus capitatus Douglas ex Hooker, Fl. Bor.-Amer. 1: 38. 1829, based on C. asper Chamisso & Schlechtendal, Linnaea 1: 14. 1826, not Nuttall 1818
Biennials or perennials; (short-lived). Trichomes of leaves 2-4(-7)-rayed. Stems erect, often branched distally, sometimes proximally, (0.5-)1.2-10(-12) dm. Basal leaves (often withered by flowering); blade spatulate to narrowly oblanceolate or linear, 2-18(-27) cm × 3-15(-30) mm, base attenuate, margins entire or dentate to denticulate, apex acute. Cauline leaves (distal) sessile; blade margins entire or denticulate. Racemes considerably elongated in fruit. Fruiting pedicels divaricate to ascending, stout or slender, narrower than fruit, 4-17(-25) mm. Flowers: sepals narrowly oblong, 7-14 mm, lateral pair saccate basally; petals usually orange to yellow, rarely lavender or purplish, suborbicular to obovate, 12-25 (-30) × (5-)6-10(-13) mm, claw 8-16 mm, apex rounded; median filaments 9-18 mm; anthers linear, 3-4 mm. Fruits divaricate or ascending to erect, narrowly linear, straight or curved upward, not torulose, 3.5-11(-15) cm × 1.3-3.3 mm, 4-angled to latiseptate, not striped; valves with prominent midvein, pubescent outside, trichomes 2-5-rayed, glabrous inside; ovules (40-)54-82 per ovary; style cylindrical, usually stout, rarely slender, 0.2-2.5(-3) mm, sparsely pubescent; stigma 2-lobed, lobes as long as wide. Seeds oblong, 1.5-4 × 1-2 mm; winged apically or not winged. 2n = 36.
Varieties 2 (2 in the flora): North America, n Mexico.