Boechera subpinnatifida |
Boechera peirsonii |
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ashy rock-cress, Klamath rockcress |
Peirson's rockcress, San Bernardino Rock cress |
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Habit | Perennials; long-lived; sexual; caudex woody (often with persistent, crowded leaf bases). | Perennials; long-lived; (cespitose); apomictic; caudex woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 1–4(–5) dm, densely pubescent proximally, trichomes short-stalked, 2–6-rayed, 0.1–0.2 mm, sparsely pubescent distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, 1–2.5 dm, glabrous or sparsely pubescent proximally, trichomes short-stalked, 2–5-rayed (rarely, some simple), 0.4–0.6 mm, glabrous distally. |
Basal leaves | blade narrowly oblanceolate, 1–4(–5) mm wide, margins prominently dentate to subpinnatifid (leaf margins of sterile shoots often entire), ciliate near petiole base, trichomes (simple or 2-rayed), 0.4–0.6 mm, surfaces densely pubescent, trichomes short-stalked, (2–)4–9-rayed, 0.05–0.2 mm. |
blade oblanceolate, 2.5–6 mm wide, margins entire, ciliate proximally, trichomes (simple), surfaces densely pubescent, trichomes short-stalked, 4–7-rayed, 0.3–0.5 mm. |
Cauline leaves | (10–)20–60, often concealing stem throughout; blade auricles 0.5–3 mm, surfaces of distalmost leaves moderately to sparsely pubescent. |
3–12, often concealing stem proximally; blade auricles 0.5–2 mm, surfaces of distalmost leaves usually glabrous, sometimes margins ciliate. |
Racemes | 8–30-flowered, usually unbranched. |
12–25-flowered, usually unbranched. |
Flowers | divaricate-ascending to pendent at anthesis; sepals pubescent; petals usually purple, rarely lavender, 9–14 × 1.5–3 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals pubescent; petals purple, 5–6 × 1.5–2 mm, glabrous; pollen spheroid. |
Fruiting pedicels | reflexed, strongly recurved, 5–15 mm, pubescent, trichomes appressed, branched. |
ascending to divaricate-descending, straight, 2–6 mm, glabrous. |
Fruits | pendent, not appressed to rachis, not secund, straight to slightly curved, edges parallel, (3.5–)5–8 cm × (1.6–)2–3 mm; valves pubescent throughout; ovules 24–42 per ovary; style 0.5–1 mm. |
ascending to divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 2–3.7 cm × 2–2.8 mm; valves glabrous; ovules 56–80 per ovary; style 0.1–0.3 mm. |
Seeds | uniseriate, 2.5–3.5 × 1.5–2.2 mm; wing continuous or at both ends, 0.4–0.8 mm wide. |
uniseriate, 1–1.5 × 0.8–1 mm; wing distal or continuous, 0.05–0.1 mm wide. |
2n | = 14. |
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Boechera subpinnatifida |
Boechera peirsonii |
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Phenology | Flowering Mar–May. | Flowering Jun–Sep. |
Habitat | Rock outcrops, talus, gravelly soil, often in sagebrush-grassland communities | Granitic ledges and talus slopes |
Elevation | 800-2400 m (2600-7900 ft) | 2700-3400 m (8900-11200 ft) |
Distribution |
CA; ID; NV; OR; UT
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CA |
Discussion | Originally thought to be restricted to northern California and adjacent Oregon, Boechera subpinnatifida is a sexual species that recently has been found in central Idaho, northern Nevada, and northwestern Utah. It appears to intergrade with both B. puberula and B. retrofracta, and species boundaries within this complex need further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera peirsonii is an apomictic species of unknown origin; although previously treated as a variety of Arabis (B.) breweri, it is quite distinct from that taxon (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). All known collections come from the San Bernardino Mountains of southern California, ca. 200 km distant from the nearest populations of B. breweri. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 409. | FNA vol. 7, p. 394. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis subpinnatifida | Arabis breweri var. pecuniaria |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 389. (2003) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 270. (2007) |
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