Boechera repanda |
Boechera shevockii |
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Greene's rockcress, Yosemite rockcress |
Shevock's rockcress |
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Habit | Perennials; short- to long-lived; sexual; caudex usually not woody. | Perennials; long-lived; (pulvinate); sexual; caudex woody (with persistent, crowded leaf bases). |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, (1–)2–9 dm, densely pubescent proximally, trichomes short- to long-stalked, 2–6-rayed, 0.2–0.5 mm, rarely mixed with simple ones, to 1.5 mm, glabrous or sparsely pubescent distally. |
1 per caudex branch, arising from center of rosette near ground surface, 0.5–1 dm, puberulent proximally, trichomes (scattered), simple, 0.02–0.1 mm, similarly pubescent distally. |
Basal leaves | blade broadly oblanceolate to obovate, 7–25(–50) mm wide, margins usually repand to coarsely dentate, rarely entire, not ciliate, surfaces moderately to densely pubescent, trichomes short- to long-stalked, 3–6-rayed, 0.2–0.5 mm. |
blade oblong-oblanceolate, 1–2 mm wide, margins entire, ciliate distally, trichomes (simple), 0.02–0.1 mm, surfaces glabrous. |
Cauline leaves | (3–)8–30, not concealing stem; blade auricles absent, surfaces of distalmost leaves sparsely pubescent. |
3–7, not concealing stem; blade auricles absent, surfaces of distalmost leaves glabrous. |
Racemes | 7–25-flowered, sometimes branched. |
4–7-flowered, unbranched. |
Flowers | erect to ascending at anthesis; sepals glabrous or sparsely pubescent; petals white, 3.5–6 × 0.8–1 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals glabrous; petals lavender, 4–5 × 1–1.2 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | erect to divaricate-ascending, straight, 3–10 mm, glabrous or pubescent, trichomes spreading, usually 2–5-rayed, rarely simple. |
ascending, straight, 5–9 mm, glabrous. |
Fruits | divaricate-ascending, not appressed to rachis, not secund, usually curved, rarely straight, edges parallel, (3.5–)5–13.5 cm × 2.5–4 mm; valves glabrous or pubescent throughout; ovules 34–50 per ovary; style 0.5–1.5 mm. |
ascending, not appressed to rachis, not secund, straight, edges parallel, 2.5–3 cm × 1–1.5 mm; valves glabrous; ovules 30–34 per ovary; style ca. 0.5 mm. |
Seeds | uniseriate, 2.5–5(–6) × 2–3(–3.5) mm; wing continuous, 0.7–1.8 mm wide. |
uniseriate, ca. 1.2 × 0.8 mm; wing distal or continuous, ca. 0.1 mm wide. |
2n | = 14. |
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Boechera repanda |
Boechera shevockii |
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Phenology | Flowering Jun–Jul. | Flowering Jun. |
Habitat | Rock outcrops, talus, and gravelly soil in meadows and open pine forests | Ledges of rock outcrops |
Elevation | 1600-3500 m (5200-11500 ft) | ca. 2500 m (ca. 8200 ft) |
Distribution |
CA; NV
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CA |
Discussion | Boechera repanda is a sexual diploid that is distinguished from all other western North American species by its wide (10–50 mm), repand to coarsely dentate basal leaves. The form recognized as var. greenei appears to be a growth response to ecologically marginal habitats. Boechera repanda occurs sporadically in the Sierra Nevada and Transverse Ranges of California, and barely extends into the Carson Range in western Nevada. Arabis inamoena Greene (1911), not Greene (1908) is an illegitimate name, sometimes found in synonymy with Boechera repanda. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera shevockii is a close relative of B. davidsonii, from which it is readily distinguished by having puberulent (versus glabrous) stems, shorter (4–5 versus 6–10 mm) petals, and much shorter (5–7 versus 30–80 mm) basal leaves. It is known only from the type specimen, from the southern Sierra Nevada in Tulare County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 402. | FNA vol. 7, p. 406. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis repanda, Arabis repanda var. greenei | |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 388. (2003) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 82. (2006) |
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