16. Boechera crandallii (B. L. Robinson) W. A. Weber, Phytologia. 51: 369. 1982.
Arabis crandallii B. L. Robinson, Bot. Gaz. 28: 135. 1899; A. stenoloba Greene
Perennials; long-lived; (often cespitose); sexual; caudex somewhat woody. Stems usually 2-5 per caudex branch, arising from margin of rosette near ground surface, (1-)1.5-4 dm, densely pubescent proximally, trichomes short-stalked, 5-8-rayed, 0.1-0.2 mm, moderately to sparsely pubescent distally. Basal leaves: blade narrowly oblanceolate, 1.5-3(-5) mm wide, margins entire, ciliate along petiole base, trichomes (simple), to 0.6 mm, surfaces densely pubescent, trichomes short-stalked, 5-8-rayed 0.1-0.2 mm. Cauline leaves: 5-14, not concealing stem; blade auricles 0.1-0.5 mm, surfaces of distalmost leaves pubescent. Racemes 10-30-flowered, usually unbranched. Fruiting pedicels ascending to divaricate-ascending, straight, 5-10 mm, pubescent, trichomes branched. Flowers ascending at anthesis; sepals pubescent; petals usually white, 5-7 × 1-2 mm, glabrous; pollen ellipsoid. Fruits ascending to divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 3-5.5 cm × 0.9-1.2 mm; valves glabrous; ovules 56-84 per ovary; style 0.1-0.5 mm. Seeds uniseriate, 0.8-1 × 0.6-0.9 mm; wing continuous (rarely absent), to 0.1 mm wide. 2n = 14.
Flowering May-Jun. Rocky slopes and gravelly soil in sagebrush, mountain shrub, open conifer forests; of conservation concern; 2000-2700 m; Colo.
Boechera crandallii is a sexual diploid known only from the Gunnison Basin of west-central Colorado. Despite its narrow range, the species appears to hybridize frequently, most notably with B. pallidifolia.