Arabis porphyrea Wooton & Standley, Contr. U.S. Natl. Herb. 16: 123. 1913

Perennials; usually long-lived; apomictic; caudex often woody. Stems 1 to several per caudex branch, arising from center of rosette or arising laterally proximal to sterile shoots, somewhat elevated on woody base or from ground surface, 2-5 (-9) dm, usually glabrous proximally, rarely sparsely pubescent, trichomes simple and short-stalked, 2- or 3-rayed, 0.1-0.5 mm, glabrous distally. Basal leaves: blade oblanceolate, (3-)5-15 mm wide, margins dentate, ciliate at least along petiole, trichomes to 1 mm, surfaces pubescent, trichomes short-stalked, 2-6-rayed, 0.1-0.5 mm. Cauline leaves: 5-17(-21), sometimes concealing stem proximally; blade auricles 0.5-3.5(-5.5) mm, surfaces of distalmost leaves glabrous. Racemes 10-30(-70)-flowered, usually unbranched. Fruiting pedicels horizontal, gently curved downward, 10-27 mm, glabrous. Flowers ascending at anthesis; sepals glabrous; petals lavender, 6.5-8.5 × 1-2.5 mm, glabrous; pollen spheroid. Fruits widely pendent, not appressed to rachis, not secund, usually curved, edges parallel, 3-7 cm × 1.8-2.5 mm; valves glabrous; ovules 100-160 per ovary; style 0.2-0.5 mm. Seeds sub-biseriate, 1.1-1.6 × 0.9-1.1 mm; wing continuous, 0.1-0.2 mm wide.

Flowering late Mar-early May. Rocky slopes in evergreen woodlands or desert scrub; 1200-2100 m; N.Mex., Tex.

Morphological evidence suggests that Boechera porphyrea is an apomictic species that arose through hybridization between B. texana and B. perennans (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison).