71. Boechera pendulocarpa (A. Nelson) Windham & Al-Shehbaz, Harvard Pap. Bot. 11: 77. 2006; Arabis pendulocarpa A. Nelson, Bot. Gaz. 30: 192. 1900; A. holboellii Hornemann var. pendulocarpa (A. Nelson) Rollins, Rhodora 43: 446. 1941; Boechera holboellii (Hornemann) Á. Löve & D. Löve var. pendulocarpa (A. Nelson) N. Snow, Madroño 52: 62. 2005. TYPE: United States, Wyoming: Yellowstone National Park, Madison River, on cliffs and rocky ridges, 23 Jun 1899, A. Nelson & E. Nelson 5504 (lectotype, designated by Rollins (1941: 446), RM!; isolectotypes, E!, GH!, K!, MO!, NY!, RM!, US!).
Plants short- to long-lived perennials, with mostly non-woody caudices, lacking crowded, persistent leaf bases; sexual, with ellipsoid pollen. Stems usually 1 per caudex branch, arising near ground surface from center of basal rosettes, 0.6–3 dm, lower parts densely with abundant simple and stalked, 2–4-rayed trichomes 0.1–0.4 mm, upper parts glabrous or sparsely pubescent. Leaves at stem bases narrowly oblanceolate, 1.5–4.0(–5.0) mm wide, entire, often ciliate on petiole with simple trichomes to 0.6 mm, blade surfaces densely pubescent with short-stalked, 4–8-rayed trichomes 0.08–0.20 mm; cauline leaves 6–17, occasionally concealing stem proximally, the uppermost glabrous or sparsely pubescent, without auricles. Inflorescences unbranched, 4–11-flowered; fruiting pedicels 3–8(–12) mm, arched, gently recurved, glabrous or with few appressed, branched trichomes. Flowers ascending at anthesis; sepals pubescent; petals white or lavender, 4–6 ´ 1.0–1.5 mm, glabrous; ovules 66–92 per fruit. Fruits (2.0–)2.5–3.8 cm ´ 1.5–2.2 mm, pendent, not appressed to rachises, not secund, usually straight, with parallel edges, glabrous; style 0.3–0.5 mm. Seeds subbiseriate, 1.0–1.2 ´ 0.7–0.9 mm; wing distal, 0.05–0.10 mm wide. 2n = 14.
Habitat: rock outcrops and gravelly slopes in sagebrush, open conifer forest, and subalpine meadows.
Elevation: 1000–3300 m.
Distribution: Canada (British Columbia, Yukon), United States (California, Idaho, Montana, Nevada, Oregon, Utah, Wyoming).
Reproductive mode: sexual diploid.