Boechera repanda |
Boechera breweri |
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Greene's rockcress, Yosemite rockcress |
Brewer's rock-cress |
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Habit | Perennials; short- to long-lived; sexual; caudex usually not woody. | Perennials; long-lived; sexual; caudex woody. | ||||
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. |
usually 1 per caudex branch, arising from center of rosette, somewhat elevated on woody base or from ground surface, 0.6–3.5(–4.5) dm, densely pubescent proximally, trichomes long-stalked and simple, 2-rayed (sometimes all simple), 0.4–1 mm, sparsely pubescent or glabrous distally. |
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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 oblanceolate, 3–7(–11) mm wide, margins entire or dentate, ciliate proximally, trichomes to 1 mm, surfaces densely pubescent, trichomes long-stalked, 2–4-rayed, 0.4–0.8 mm. |
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Cauline leaves | (3–)8–30, not concealing stem; blade auricles absent, surfaces of distalmost leaves sparsely pubescent. |
5–15(–28), often concealing stem proximally; blade auricles 0.5–3(–5) mm, surfaces of distalmost leaves pubescent. |
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Racemes | 7–25-flowered, sometimes branched. |
7–20(–30)-flowered, usually unbranched. |
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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 pubescent; petals usually purple (rarely lavender), 7–12 × 2–4 mm, glabrous; pollen ellipsoid. |
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Fruiting pedicels | erect to divaricate-ascending, straight, 3–10 mm, glabrous or pubescent, trichomes spreading, usually 2–5-rayed, rarely simple. |
ascending to divaricate-ascending, straight, 3–25 mm, pubescent or glabrous, trichomes spreading, simple and 2-rayed. |
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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 to divaricate-ascending, not appressed to rachis, not secund, usually curved, rarely straight, edges parallel, 3.5–10 cm × 1.5–2.2 mm; valves usually glabrous, rarely sparsely pubescent; ovules 48–96 per ovary; style 0.05–0.3 mm. |
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Seeds | uniseriate, 2.5–5(–6) × 2–3(–3.5) mm; wing continuous, 0.7–1.8 mm wide. |
uniseriate, 1.2–1.7 × 1–1.2 mm; wing continuous, 0.1–0.2 mm wide distally. |
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2n | = 14. |
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Boechera repanda |
Boechera breweri |
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Phenology | Flowering Jun–Jul. | |||||
Habitat | Rock outcrops, talus, and gravelly soil in meadows and open pine forests | |||||
Elevation | 1600-3500 m (5200-11500 ft) | |||||
Distribution |
CA; NV
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CA; OR
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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.) |
Subspecies 2 (2 in the flora). Relatively few other sexual diploid species of Boechera co-occur with B. breweri, and the only currently recognized hybrid involving this taxon is B. rubicundula (= B. arcuata × B. breweri; M. D. Windham and I. A. Al-Shehbaz 2007). Boechera breweri appears to be related to B. sparsiflora, and some specimens of subsp. shastaensis can be difficult to separate from that species. The two subspecies appear to intergrade on the western side of the Sacramento Valley from Tehama to Solano counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 7, p. 402. | FNA vol. 7, p. 367. | ||||
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Arabis repanda, Arabis repanda var. greenei | Arabis breweri, Arabis breweri var. figularis, Arabis epilobioides | ||||
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 388. (2003) | (S. Watson) Al-Shehbaz: Novon 13: 384. (2003) | ||||
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