41. Boechera gunnisoniana (Rollins) W. A. Weber, Phytologia 51: 370. 1982; Arabis gunnisoniana Rollins, Rhodora 43: 434. 1941. TYPE: United States, Colorado, Gunnison Co., barren rocky knoll near Saguache Creek, 6 miles E of Gunnison, 8000 ft (2400 m), 21 May 1938, Reed C. Rollins 2090 (holotype, GH!; isotype, BM!, BRY!, CAN!, DAO!, E!, MO!, NY!, OSC!, 2PH!, RM!, UC!, WS!).

     Plants mostly long-lived, cespitose perennials often with woody caudices, lacking crowded, persistent leaf bases; sexual, with ellipsoid pollen. Stems usually 2–6 per caudex branch, arising near ground surface from margin of basal rosettes, 0.8–2(–2.5) dm, lower parts with abundant short-stalked, 2–4-rayed trichomes 0.08–0.3 mm and fewer simple trichomes, upper parts sparsely pubescent or rarely glabrous. Leaves at stem bases linear-oblanceolate, 1–3(–4) mm wide, entire, ciliate proximally with trichomes to 0.8 mm, blade surfaces densely pubescent with short-stalked, 3–6-rayed trichomes 0.08–0.3 mm; cauline leaves 3–9, not concealing stem, the uppermost glabrous or sparsely pubescent, with auricles 0.2–1 mm. Inflorescences mostly unbranched, 7–15-flowered; fruiting pedicels 4–7 mm, divaricate, straight or slightly curved, glabrous or with few appressed, branched trichomes. Flowers divaricate-ascending at anthesis; sepals pubescent; petals white or lavender, 4–6 ´ 1–2 mm, glabrous; ovules 36–54 per fruit. Fruits 2.5–4.0 cm ´ 1.0–1.5 mm, horizontal to divaricate-descending, not appressed to rachises, not secund, straight to slightly curved, with parallel edges, glabrous; style 0.1–0.2 mm. Seeds uniseriate, 1.0–1.2 ´ 0.8–1.0 mm; wing continuous, 0.10–0.15 mm wide. 2n = 14.

Flowering: May–Jun.

Habitat: rocky slopes and knolls with sagebrush.

Elevation: 2100–2700 m.

Distribution: United States (Colorado/Gunnison County).

Reproductive mode: sexual diploid.