Boechera lasiocarpa |
Boechera shevockii |
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Shevock's rockcress |
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Habit | Perennials; long-lived; sexual; caudex often woody. | Perennials; long-lived; (pulvinate); sexual; caudex woody (with persistent, crowded leaf bases). |
Stems | 1 or few per caudex branch, arising from center or margin of rosette, somewhat elevated on woody base or near ground surface, (0.7–)2–3.5 dm, densely pubescent proximally, trichomes short-stalked, 4–8-rayed, 0.05–0.15 mm, moderately to 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 narrowly oblanceolate, 2–5 mm wide, margins entire, not ciliate, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.05–0.15 mm. |
blade oblong-oblanceolate, 1–2 mm wide, margins entire, ciliate distally, trichomes (simple), 0.02–0.1 mm, surfaces glabrous. |
Cauline leaves | 4–10, often concealing stem proximally; blade auricles absent, surfaces of distalmost leaves sparsely to moderately pubescent. |
3–7, not concealing stem; blade auricles absent, surfaces of distalmost leaves glabrous. |
Racemes | 5–12-flowered, usually unbranched. |
4–7-flowered, unbranched. |
Flowers | divaricate at anthesis; sepals pubescent; petals purple to lavender, 6–10 × 1.5–2.5 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals glabrous; petals lavender, 4–5 × 1–1.2 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | descending, recurved, 4–14 mm, pubescent, trichomes appressed, branched. |
ascending, straight, 5–9 mm, glabrous. |
Fruits | pendent, usually not appressed to rachis, rarely secund, straight or curved, 2–5 cm × 1.7–2.2 mm; valves glabrous or pubescent throughout; ovules 26–36 per ovary; style 0.2–0.9 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, 1.5–2 × 1–1.5 mm; wing distal or continuous, 0.1–0.2 mm wide. |
uniseriate, ca. 1.2 × 0.8 mm; wing distal or continuous, ca. 0.1 mm wide. |
Boechera lasiocarpa |
Boechera shevockii |
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Phenology | Flowering May–Jun. | Flowering Jun. |
Habitat | Rocky ridges and slopes with dwarf sagebrush | Ledges of rock outcrops |
Elevation | 1800-2800 m (5900-9200 ft) | ca. 2500 m (ca. 8200 ft) |
Distribution |
UT |
CA |
Discussion | Boechera lasiocarpa is a sexual species that appears to be restricted to the Bear River Mountains and northern Wasatch Range in north-central Utah. Reports of Arabis (Boechera) lasiocarpa from central Idaho (e.g., R. C. Rollins 1993; N. H. Holmgren 2005b) represent B. rollinsiorum (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). (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. 387. | FNA vol. 7, p. 406. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis lasiocarpa | |
Name authority | (Rollins) Dorn: Brittonia 55: 3. (2003) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 82. (2006) |
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