Boechera rollinsiorum

Perennials; long-lived; sexual; caudex woody. Stems usually 3-5 per caudex branch, arising from margin of rosette, elevated above ground surface on woody base, 1-2.5 dm, densely pubescent proximally, trichomes short-stalked, 2-4 (or 5)-rayed, 0.2-0.4 mm, moderately to sparsely pubescent distally. Basal leaves: blade oblanceolate, 3-5 mm wide, margins entire, ciliate proximally, trichomes (simple), to 0.6 mm, surfaces densely pubescent, trichomes short-stalked, 2-4 (or 5)- rayed, 0.15-0.4 mm. Cauline leaves: 5-9, not concealing stem; blade auricles 0.5-1 mm, surfaces of distalmost leaves sparsely to moderately pubescent. Racemes 5-11-flowered, usually unbranched. Fruiting pedicels descending, straight to slightly recurved, 4-6 mm, pubescent, trichomes appressed, branched. Flowers divaricate-ascending at anthesis; sepals pubescent; petals pale purple, 6-8 × 1.5-2 mm, glabrous; pollen ellipsoid. Fruits (immature) pendent, not appressed to rachis, not secund, straight, edges parallel; valves glabrous. Seeds not seen.

Flowering Jun. Metamorphosed igneous gravel on steep slopes; ca. 2100 m; Idaho.

Boechera rollinsiorum shows superficial similarities to both B. glareosa and B. lasiocarpa (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). It is known thus far only from the type collection below Galena Summit in central Idaho.