Harvard Pap. Bot. 12: 237. 2007
Perennials; long-lived; apomictic; caudex woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 0.5–2.5 dm, glabrous throughout. Basal leaves: blade oblanceolate, 1.5–5 mm wide, margins entire, ciliate proximally, trichomes (simple), to 0.4 mm, and distally, trichomes short-stalked, 2 or 3 (or 4)-rayed, 0.15–0.4 mm, surfaces glabrous. Cauline leaves: 2–7, not concealing stem; blade with auricles 0.2–1 mm, auricles rarely absent, surfaces of distalmost leaves glabrous. Racemes 2–9-flowered, unbranched. Fruiting pedicels ascending to suberect, straight, 6–20 mm, glabrous. Flowers ascending at anthesis; sepals glabrous; petals lavender to purplish, 5–6 × 1–2 mm, glabrous; pollen spheroid. Fruits ascending to suberect, rarely appressed to rachis, not secund, straight, edges slightly undulate (rarely parallel), 3.5–5 cm × 3–5 mm; valves glabrous; ovules 18–30 per ovary; style 0.2–1 mm. Seeds uniseriate, 4–5 × 3–4 mm; wing continuous, 1–1.5 mm wide.
Phenology: Flowering Jul–Aug.
Habitat: Rocky slopes in alpine meadows and open coniferous forests
Elevation: 2200-3500 m
Calif., Nev., Oreg.
Morphological evidence suggests that Boechera covillei is an apomictic species that arose through hybridization between B. howellii and B. lyallii (see M. D. Windham and I. A. Al-Shehbaz 2007b for detailed comparison).