Boechera repanda |
Boechera cusickii |
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Greene's rockcress, Yosemite rockcress |
Cusick's rock-cress |
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Habit | Perennials; short- to long-lived; sexual; caudex usually not woody. | Perennials; long-lived; (often cespitose); sexual; caudex usually 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 near ground surface, 1–2.5(–3.8) dm, densely pubescent proximally, trichomes simple, 0.5–1.5 mm, sparsely pubescent or glabrous 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 linear to narrowly oblanceolate, 0.5–2 mm wide, margins entire, ciliate, trichomes (simple), 1–1.7 mm, surfaces moderately pubescent, trichomes simple and long-stalked, 2-rayed, 0.5–1.7 mm. |
Cauline leaves | (3–)8–30, not concealing stem; blade auricles absent, surfaces of distalmost leaves sparsely pubescent. |
10–30, often concealing stem proximally; blade auricles 0–0.5 mm, surfaces of distalmost leaves sparsely pubescent. |
Racemes | 7–25-flowered, sometimes branched. |
5–14-flowered, usually 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 pubescent; petals white to lavender, 6–10 × 2–3 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, 4–15(–20) mm, glabrous or sparsely pubescent, trichomes simple. |
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, straight or curved, edges parallel, 4–8(–9.5) cm × 2.3–3 mm; valves glabrous; ovules 56–106 per ovary; style 0.1–0.5 mm. |
Seeds | uniseriate, 2.5–5(–6) × 2–3(–3.5) mm; wing continuous, 0.7–1.8 mm wide. |
uniseriate, 1.5–2.5 × 1.5–2 mm; wing continuous, 0.1–0.2 mm wide distally. |
2n | = 14. |
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Boechera repanda |
Boechera cusickii |
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Phenology | Flowering Jun–Jul. | Flowering Apr-mid May. |
Habitat | Rock outcrops, talus, and gravelly soil in meadows and open pine forests | Basaltic bluffs, rocky slopes, rock crevices, gravelly hillsides, sagebrush hills, outcrops of volcanic rock |
Elevation | 1600-3500 m (5200-11500 ft) | 600-1800 m (2000-5900 ft) |
Distribution |
CA; NV
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ID; NV; OR; WA
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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.) |
Peripheral populations of Boechera cusickii in south-central Idaho and northern Nevada have a higher proportion of branched hairs, possibly resulting from hybridization with B. sparsiflora. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 402. | FNA vol. 7, p. 372. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis repanda, Arabis repanda var. greenei | Arabis cusickii |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 388. (2003) | (S. Watson) Al-Shehbaz: Novon 13: 384. (2003) |
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