Boechera subpinnatifida |
Boechera rectissima |
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ashy rock-cress, Klamath rockcress |
bristly-leaf rock-cress |
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Habit | Perennials; long-lived; sexual; caudex woody (often with persistent, crowded leaf bases). | Biennials or perennials; short-lived; sexual; caudex present or absent. |
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, 2–8(–10) dm, usually glabrous proximally, rarely sparsely pubescent, trichomes simple, to 0.7 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, 3–8(–13) mm wide, margins entire or denticulate, ciliate, trichomes (simple), 0.5–1.2 mm, surfaces sparsely to densely pubescent, trichomes simple, to 0.8 mm, often mixed with short-stalked, 2- or 3-rayed ones, 0.15–0.5 mm. |
Cauline leaves | (10–)20–60, often concealing stem throughout; blade auricles 0.5–3 mm, surfaces of distalmost leaves moderately to sparsely pubescent. |
6–30(–45), often concealing stem proximally; blade auricles 1–1.5 mm, surfaces of distalmost leaves sparsely pubescent, sometimes margins ciliate. |
Racemes | 8–30-flowered, usually unbranched. |
10–30(–50)-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. |
pendent at anthesis; sepals pubescent; petals white, 3–4 × 0.7–1.2 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | reflexed, strongly recurved, 5–15 mm, pubescent, trichomes appressed, branched. |
reflexed, abruptly recurved at base, otherwise straight, 4–10 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. |
strongly reflexed, usually appressed to rachis, not secund, straight, edges parallel, 5–9 cm × 1.8–2.5 mm; valves glabrous; ovules 46–80 per ovary; style 0.2–0.8 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, 1.8–2.1 × 1–1.5 mm; wing continuous, 0.15–0.25 mm wide. |
2n | = 14. |
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Boechera subpinnatifida |
Boechera rectissima |
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Phenology | Flowering Mar–May. | Flowering May–Jul. |
Habitat | Rock outcrops, talus, gravelly soil, often in sagebrush-grassland communities | Rocky slopes in open conifer forests |
Elevation | 800-2400 m (2600-7900 ft) | 1500-2500 m (4900-8200 ft) |
Distribution |
CA; ID; NV; OR; UT
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CA; OR
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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 rectissima is easily recognized by its combination of glabrous stems, basal leaves with large, predominantly simple trichomes, short (3–4 mm), white petals, and strongly reflexed, appressed fruits. Plants assigned to var. simulans appear to be hybrids between this species and B. retrofracta. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 409. | FNA vol. 7, p. 401. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis subpinnatifida | Arabis rectissima, Arabis setigera, Arabis wyndii |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 389. (2003) | (Greene) Al-Shehbaz: Novon 13: 388. (2003) |
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