Boechera rectissima |
Boechera schistacea |
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bristly-leaf rock-cress |
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Habit | Biennials or perennials; short-lived; sexual; caudex present or absent. | Perennials; long-lived; sexual; caudex woody. |
Stems | 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. |
usually 2–5 per caudex branch, arising from margin of rosette, elevated above ground surface on woody base, 0.8–2.5(–4) dm, glabrous throughout. |
Basal leaves | 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. |
blade linear to narrowly oblanceolate, 1.2–2.5 mm wide, margins entire, ciliate proximally, trichomes (simple), 0.3–0.7 mm, surfaces glabrous or sparsely pubescent, trichomes short-stalked, 2- or 3-rayed, 0.2–0.5 mm. |
Cauline leaves | 6–30(–45), often concealing stem proximally; blade auricles 1–1.5 mm, surfaces of distalmost leaves sparsely pubescent, sometimes margins ciliate. |
2–5(–9), not concealing stem; blade auricles 0.2–0.5 mm, surfaces of distalmost leaves glabrous. |
Racemes | 10–30(–50)-flowered, usually unbranched. |
5–12-flowered, usually unbranched. |
Flowers | pendent at anthesis; sepals pubescent; petals white, 3–4 × 0.7–1.2 mm, glabrous; pollen ellipsoid. |
divaricate-ascending at anthesis; sepals glabrous; petals white to lavender, 4–6 × 1–1.5 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | reflexed, abruptly recurved at base, otherwise straight, 4–10 mm, glabrous. |
reflexed, curved, 5–9 mm, glabrous. |
Fruits | 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. |
pendent, not appressed to rachis, not secund, straight, edges parallel, 1.8–4.5 cm × 1.5–2 mm; valves glabrous; ovules 24–36 per ovary; style 0.2–0.5 mm. |
Seeds | uniseriate, 1.8–2.1 × 1–1.5 mm; wing continuous, 0.15–0.25 mm wide. |
uniseriate, 0.9–1.2 × 0.7–0.9 mm; not winged. |
2n | = 14. |
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Boechera rectissima |
Boechera schistacea |
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Phenology | Flowering May–Jul. | Flowering May–Jul. |
Habitat | Rocky slopes in open conifer forests | Rocky slopes and gravelly soil in sagebrush, open conifer forests, and subalpine meadows |
Elevation | 1500-2500 m (4900-8200 ft) | 2400-3200 m (7900-10500 ft) |
Distribution |
CA; OR
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NV; UT |
Discussion | 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.) |
Boechera schistacea is a sexual diploid that appears to intergrade with B. pendulina where their geographic ranges overlap in southwestern Utah. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 401. | FNA vol. 7, p. 404. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis rectissima, Arabis setigera, Arabis wyndii | Arabis schistacea |
Name authority | (Greene) Al-Shehbaz: Novon 13: 388. (2003) | (Rollins) Dorn: Brittonia 55: 3. (2003) |
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