Boechera pygmaea |
Boechera schistacea |
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Tulare County rock cress |
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Habit | Perennials; usually long-lived; sexual; caudex woody, (often with persistent, crowded leaf bases). | Perennials; long-lived; sexual; caudex woody. |
Stems | usually 2–5 per caudex branch, arising from margin of rosette near ground surface, or arising laterally proximal to sterile shoots, 0.2–0.8 dm, pubescent proximally, trichomes simple and short-stalked, 2- or 3-rayed, to 0.4 mm, glabrescent 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 linear, 0.8–1.5 mm wide, margins entire, ciliate, trichomes (simple and spurred), to 0.8 mm, surfaces moderately pubescent, trichomes short-stalked, 2–4-rayed, 0.05–0.4 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 | 2–4, not concealing stem; blade auricles absent, surfaces of distalmost leaves pubescent. |
2–5(–9), not concealing stem; blade auricles 0.2–0.5 mm, surfaces of distalmost leaves glabrous. |
Racemes | 2–5-flowered, unbranched. |
5–12-flowered, usually unbranched. |
Flowers | erect at anthesis; sepals pubescent; petals white, 3.5–5 × 0.7–1 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 | erect to ascending, straight, 2–7 mm, usually pubescent, rarely glabrous, trichomes subappressed, branched. |
reflexed, curved, 5–9 mm, glabrous. |
Fruits | erect to ascending, often appressed to rachis, not secund, straight, edges parallel, (1.3–)2–3.3 cm × 4–5 mm; valves glabrous; ovules 8–12 per ovary; style 0.05–0.4 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, 3–5 × 2.5–4.5 mm; wing continuous, 0.8–2 mm wide distally. |
uniseriate, 0.9–1.2 × 0.7–0.9 mm; not winged. |
2n | = 14. |
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Boechera pygmaea |
Boechera schistacea |
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Phenology | Flowering May–Jul. | Flowering May–Jul. |
Habitat | Barren flats of arkosic gravel | Rocky slopes and gravelly soil in sagebrush, open conifer forests, and subalpine meadows |
Elevation | 2400-3200 m (7900-10500 ft) | 2400-3200 m (7900-10500 ft) |
Distribution |
CA |
NV; UT |
Discussion | Of conservation concern. Despite the distinctive morphology of Boechera pygmaea, there is evidence that it is capable of producing fertile hybrids with B. stricta. It is known only from Inyo and Tulare counties in the southern Sierra Nevada. (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 | ||
Sibling taxa | ||
Synonyms | Arabis pygmaea | Arabis schistacea |
Name authority | (Rollins) Al-Shehbaz: Novon 13: 388. (2003) | (Rollins) Dorn: Brittonia 55: 3. (2003) |
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