Arabis pratincola Greene, Repert. Spec. Nov. Regni Veg. 5: 244. 1908; A. drummondii A. Gray var. pratincola (Greene) M. Hopkins; A. nemophila Greene

Perennials; usually short-lived; apomictic; caudex not woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 2-6 dm, pubescent proximally, trichomes sessile, 2- or 3-rayed, 0.15-0.6 mm, glabrous distally. Basal leaves: blade oblanceolate, 1.5-5(-7) mm wide, margins usually entire, rarely denticulate, ciliate at petiole base, trichomes to 0.4 mm, surfaces pubescent, trichomes sessile, 2-4(-6)-rayed, 0.1-0.45 mm. Cauline leaves: (7-)13-42, concealing stem proximally; blade auricles 1-4 mm, surfaces of distalmost leaves sparsely pubescent apically. Racemes (7-)14-45-flowered, usually unbranched. Fruiting pedicels erect, straight, 5-12 mm, glabrous. Flowers ascending at anthesis; sepals glabrous; petals lavender, 6-10 × 1.5-2 mm, glabrous; pollen spheroid. Fruits erect, appressed to rachis, not secund, straight, edges parallel, 4-6.5 cm × 1.5-2 mm; valves glabrous; ovules 60-140 per ovary; style 0.1-0.3 mm. Seeds sub-biseriate, 1.4-2 × 1-1.4 mm; wing continuous, 0.1-0.35 mm wide.

Flowering Jun-Aug. Rocky slopes and soil patches in open areas and along forest edges; 1900-3200 m; Calif., Idaho, Nev., Oreg.

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