Boechera subpinnatifida |
Boechera pinzliae |
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ashy rock-cress, Klamath rockcress |
Pinzl's Rock cress |
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Habit | Perennials; long-lived; sexual; caudex woody (often with persistent, crowded leaf bases). | Perennials; long-lived; apomictic; caudex usually 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. |
1–3 per caudex branch, arising from margin of rosette near ground surface, 0.4–1.6 dm, densely pubescent proximally, trichomes short-stalked, 2–5-rayed, 0.05–0.2 mm, glabrous or sparsely pubescent 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. |
(petiole glabrous); blade linear-oblanceolate, 1–3 mm wide, margins entire, rarely ciliate proximally, trichomes to 0.5 mm, surfaces densely pubescent, trichomes short-stalked, 2–5-rayed, 0.05–0.2 mm. |
Cauline leaves | (10–)20–60, often concealing stem throughout; blade auricles 0.5–3 mm, surfaces of distalmost leaves moderately to sparsely pubescent. |
3–6, not concealing stem; blade auricles 0(–0.3) mm, surfaces of distalmost leaves sparsely to moderately pubescent. |
Racemes | 8–30-flowered, usually unbranched. |
5–8-flowered, 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, 4–5 × 1–1.5 mm, glabrous; pollen spheroid. |
Fruiting pedicels | reflexed, strongly recurved, 5–15 mm, pubescent, trichomes appressed, branched. |
ascending to divaricate-ascending, straight, 2–6 mm, glabrous or sparsely pubescent, trichomes appressed, branched. |
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, 2.5–4.8 cm × 2.5–3.2 mm; valves glabrous; ovules 26–34 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, 2.5–3.5 × 1.5–2.5 mm; wing continuous, 0.2–0.9 mm wide. |
2n | = 14. |
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Boechera subpinnatifida |
Boechera pinzliae |
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Phenology | Flowering Mar–May. | Flowering Jul. |
Habitat | Rock outcrops, talus, gravelly soil, often in sagebrush-grassland communities | Gravelly granitic soils in alpine and subalpine areas |
Elevation | 800-2400 m (2600-7900 ft) | 3000-3400 m (9800-11200 ft) |
Distribution |
CA; ID; NV; OR; UT
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CA; NV |
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.) |
Of conservation concern. Morphological evidence suggests that Boechera pinzliae is an apomictic hybrid that contains at least one genome derived from B. platysperma; the other parent has not yet been determined. It is most similar to B. elkoensis, from which it differs in having sparsely pubescent (versus glabrous) sepals and basal leaves with stalked (versus sessile or subsessile) trichomes. Boechera pinzliae is known only from the White Mountains in extreme western Nevada (Esmeralda County) and east-central California (Mono County). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 409. | FNA vol. 7, p. 397. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis subpinnatifida | Arabis pinzliae |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 389. (2003) | (Rollins) Al-Shehbaz: Novon 13: 388. (2003) |
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