Boechera subpinnatifida |
Boechera lemmonii |
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ashy rock-cress, Klamath rockcress |
Lemmon's rock-cress, Lemmon's suncress, wind-blown suncress |
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Habit | Perennials; long-lived; sexual; caudex woody (often with persistent, crowded leaf bases). | Perennials; long-lived; (somewhat cespitose); sexual or apomictic; caudex woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 1–4(–5) dm, densely pubescent proximally, trichomes short-stalked, 2–6-rayed, 0.1–0.2 mm, sparsely pubescent distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, or arising laterally proximal to sterile shoots, 0.5–2(–2.5) dm, glabrous or sparsely pubescent proximally, trichomes short-stalked, 2–6-rayed, 0.1–0.2 mm, glabrous distally. |
Basal leaves | blade narrowly oblanceolate, 1–4(–5) mm wide, margins prominently dentate to subpinnatifid (leaf margins of sterile shoots often entire), ciliate near petiole base, trichomes (simple or 2-rayed), 0.4–0.6 mm, surfaces densely pubescent, trichomes short-stalked, (2–)4–9-rayed, 0.05–0.2 mm. |
blade oblanceolate to obovate, 1.5–5 mm wide, margins usually entire, rarely slightly dentate, ciliate along petiole, surfaces densely to sparsely pubescent, trichomes short-stalked, 3–9-rayed, 0.1–0.2 mm. |
Cauline leaves | (10–)20–60, often concealing stem throughout; blade auricles 0.5–3 mm, surfaces of distalmost leaves moderately to sparsely pubescent. |
2–8(–12), not concealing stem; blade auricles absent or 0.1–0.5 mm, surfaces of distalmost leaves glabrous or sparsely pubescent. |
Racemes | 8–30-flowered, usually unbranched. |
3–12(–17)-flowered, usually unbranched. |
Flowers | divaricate-ascending to pendent at anthesis; sepals pubescent; petals usually purple, rarely lavender, 9–14 × 1.5–3 mm, glabrous; pollen ellipsoid. |
divaricate-ascending at anthesis; sepals glabrous or sparsely pubescent; petals purple to lavender, 3.5–6 × 1–1.5 mm; pollen ellipsoid or spheroid. |
Fruiting pedicels | reflexed, strongly recurved, 5–15 mm, pubescent, trichomes appressed, branched. |
divaricate-ascending to slightly descending, usually slightly recurved, rarely straight, 2–6 mm, glabrous or sparsely pubescent, trichomes appressed, branched. |
Fruits | pendent, not appressed to rachis, not secund, straight to slightly curved, edges parallel, (3.5–)5–8 cm × (1.6–)2–3 mm; valves pubescent throughout; ovules 24–42 per ovary; style 0.5–1 mm. |
divaricate-ascending to slightly descending, not appressed to rachis, secund, straight or curved, edges parallel, (1.6–) 2–4.4 cm × 1.6–2.3 mm; valves glabrous; ovules 28 40(–44) per ovary; style 0.1–0.2 mm. |
Seeds | uniseriate, 2.5–3.5 × 1.5–2.2 mm; wing continuous or at both ends, 0.4–0.8 mm wide. |
uniseriate, 1.3–2 × 1–1.5 mm; wing continuous, 0.1–0.5 mm wide. |
2n | = 14. |
= 14. |
Boechera subpinnatifida |
Boechera lemmonii |
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Phenology | Flowering Mar–May. | Flowering Jun–Aug. |
Habitat | Rock outcrops, talus, gravelly soil, often in sagebrush-grassland communities | Cliffs, talus slopes, and gravelly soil in alpine and subalpine habitats |
Elevation | 800-2400 m (2600-7900 ft) | 2100-4400 m (6900-14400 ft) |
Distribution |
CA; ID; NV; OR; UT
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AK; CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC; YT
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Discussion | Originally thought to be restricted to northern California and adjacent Oregon, Boechera subpinnatifida is a sexual species that recently has been found in central Idaho, northern Nevada, and northwestern Utah. It appears to intergrade with both B. puberula and B. retrofracta, and species boundaries within this complex need further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera lemmonii is easily recognized by its combination of secund fruits, mat-forming habit, purplish sepals, and obovate-oblanceolate cauline leaves. Both sexual and apomictic collections are known; further study is needed to determine whether they truly are conspecific. The taxa traditionally treated as Arabis (Boechera) lemmonii vars. depauperata, drepanoloba, and paddoensis are apomictic hybrids here recognized as distinct species (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 409. | FNA vol. 7, p. 388. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis subpinnatifida | Arabis lemmonii, Arabis bracteolata, Arabis canescens var. latifolia, Arabis codyi, Arabis egglestonii, Arabis kennedyi, Arabis latifolia, Arabis oreocallis, Arabis polyclada, Arabis semisepulta |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 389. (2003) | (S. Watson) W. A. Weber: Phytologia 51: 370. (1982) |
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