Draba petrophila Greene var. viridis (A. Heller) C. L. Hitchcock

Perennials; (long-lived, cespi-tose); caudex simple or branched (densely covered with persistent petioles); not scapose. Stems unbranched or branched, 0.35-3 dm, pubescent throughout, trichomes simple, 0.2-0.8 mm, with short-stalked to subsessile, cruciform ones, 0.05-0.2 mm. Basal leaves rosulate; petiolate; petiole ciliate, (trichomes simple, 0.4-1 mm); blade oblanceolate, 1-6 cm × 2-6 mm, margins usually entire, rarely denticulate, surfaces pubescent with stalked, cruciform trichomes, 0.1-0.5 mm. Cauline leaves 5-16; sessile; blade ovate to lanceolate or oblong, margins entire or denticulate, surfaces pubescent as basal. Racemes 11-28-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem. Fruiting pedicels divaricate, straight, 4-7 mm, pubescent throughout, trichomes simple (0.1-0.4 mm) and subsessile, 2-4-rayed (0.03-0.25 mm). Flowers: sepals oblong, 2-3 mm, pubescent, (trichomes simple and 2-rayed); petals yellow, oblanceolate, 3.5-5 × 1-1.5 mm; anthers ovate, 0.5-0.6 mm. Fruits lanceolate to ovate, often plane, flattened, 3.5-8 × 2-3 mm; valves pubescent, trichomes (vertical), simple and 2-4-rayed, (0.1-)0.3-0.8 mm; ovules 12-20 per ovary; style (1.5-)2-3 mm. Seeds ovoid, 1.2-1.5 × 0.7-0.9 mm.

Flowering Aug-Sep. Open stands of pines; of conservation concern; ca. 2600 m; Ariz.; Mexico (Sonora).

Draba viridis has been reported from the Huachuca and Santa Catalina mountains in southern Arizona, and the adjacent San Jose Mountains in Sonora, Mexico. It was reduced to a variety of D. petrophila by Hitchcock and a form of D. helleriana by O. E. Schulz, but is easily separated from both (I. A. Al-Shehbaz and M. D. Windham 2007).