Boechera puberula |
Boechera villosa |
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Blue Mountain rockcress, hoary rock-cress, silver rockcress |
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Habit | Perennials; short-lived; sexual; caudex not woody. | Perennials; short-lived; sexual; caudex not woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, (1–)2–6.3 dm, densely pubescent proximally, trichomes short-stalked, 3–8-rayed, 0.1–0.3(–0.5) mm, similarly pubescent distally. |
1–3 per caudex branch, arising laterally proximal to sterile shoots near ground surface, ca. 2.5 dm, densely pubescent proximally, trichomes simple and 2-rayed, 0.25–0.7 mm, glabrescent distally. |
Basal leaves | blade oblanceolate to linear-oblanceolate, 1.5–5 mm wide, margins usually dentate, not ciliate, surfaces densely pubescent, trichomes short-stalked, 5–12-rayed, 0.05–0.2 mm. |
blade oblanceolate to obovate, 2.5–5 mm wide, margins entire, ciliate along petiole, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes simple and short-stalked, 2- or 3-rayed, 0.25–0.5 mm. |
Cauline leaves | 7–45(–65), concealing stem proximally; blade auricles absent or 0.7–3 mm, surfaces of distalmost leaves pubescent. |
4–6, not concealing stem; blade auricles ca. 1 mm, surfaces of distalmost leaves sparsely pubescent. |
Racemes | 10–40(–64)-flowered, usually unbranched. |
6–10-flowered, unbranched. |
Flowers | ascending to descending at anthesis; sepals pubescent; petals white to lavender, 5–9 × 0.8–1.8 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals pubescent; petals lavender, 4–5 × 1–1.5 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | pendent, recurved distal to horizontal to ascending base, 4–10 mm, pubescent, trichomes appressed, branched. |
ascending, straight, 6–10 mm, glabrous or sparsely pubescent, trichomes subappressed, branched. |
Fruits | closely pendent, rarely appressed to rachis, sometimes somewhat secund, usually straight, edges parallel, 3–6.5 cm × 1.9–2.2 mm; valves pubescent throughout; ovules 38–64 per ovary; style 0.05–0.1 mm. |
divaricate-ascending, not appressed to rachis, not secund, slightly curved, edges parallel, 4–5 cm × ca. 1 mm; valves glabrous; ovules ca. 64 per ovary; style ca. 0.2 mm. |
Seeds | uniseriate, 1.4–1.8 × 1–1.4 mm; wing continuous, 0.1–0.3 mm wide. |
uniseriate, (none mature). |
2n | = 14. |
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Boechera puberula |
Boechera villosa |
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Phenology | Flowering Apr–Jul. | Flowering May. |
Habitat | Ledges, rocky slopes, gravelly hillsides in sagebrush, pinyon-juniper, and mountain shrub communities | Basalt outcrop in pinyon-juniper woodlands |
Elevation | 1300-2900 m (4300-9500 ft) | ca. 2100 m (ca. 6900 ft) |
Distribution |
CA; NV; OR; UT
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NM |
Discussion | Boechera puberula is a diploid species that appears to intergrade with both B. retrofracta and B. subpinnatifida. The glabrous-fruited specimens discussed by R. C. Rollins (1993) represent apomictic hybrids with other species, primarily B. pendulocarpa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera villosa is known only from the type collection from the Rio Grande Gorge in Taos County. The holotype was originally identified as Arabis (Boechera) perennans but clearly is more closely related to B. pallidifolia (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 399. | FNA vol. 7, p. 411. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis puberula, Arabis arida, Arabis beckwithii, Arabis lignipes var. impar, Arabis sabulosa, Arabis subpinnatifida var. beckwithii, Arabis subpinnatifida var. impar, B. beckwithii | |
Name authority | (Nuttall) Dorn: Brittonia, 55: 3. (2003) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 86. (2006) |
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