Boechera subpinnatifida |
Boechera duchesnensis |
|
---|---|---|
ashy rock-cress, Klamath rockcress |
|
|
Habit | Perennials; long-lived; sexual; caudex woody (often with persistent, crowded leaf bases). | Perennials; usually long-lived; apomictic; caudex often 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, elevated on woody base or from near ground surface, 1.5–4.5 dm, densely pubescent proximally, trichomes short-stalked, 2–7-rayed, 0.2–0.5 mm (sometimes mixed with some larger trichomes proximally), sparsely pubescent 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 linear-oblanceolate, 2–5 mm wide, margins entire or denticulate, ciliate at petiole base, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.15–0.4 mm. |
Cauline leaves | (10–)20–60, often concealing stem throughout; blade auricles 0.5–3 mm, surfaces of distalmost leaves moderately to sparsely pubescent. |
3–8, not concealing stem; blade auricles 0.7–2 mm, surfaces of distalmost leaves sparsely pubescent. |
Racemes | 8–30-flowered, usually unbranched. |
11–22-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 pubescent; petals whitish to pale lavender, 7–10 × 1.5–3 mm, glabrous; pollen spheroid. |
Fruiting pedicels | reflexed, strongly recurved, 5–15 mm, pubescent, trichomes appressed, branched. |
horizontal, straight or slightly curved, 7–14 mm, 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. |
horizontal, not appressed to rachis, not secund, usually straight, edges parallel, 3.5–5 cm × 1.7–2 mm; valves glabrous proximally, pubescent distally; ovules 72–92 per ovary; style 0.1–0.3 mm. |
Seeds | uniseriate, 2.5–3.5 × 1.5–2.2 mm; wing continuous or at both ends, 0.4–0.8 mm wide. |
sub-biseriate, 1.1–1.3 × 0.7–1 mm; wing continuous, ca. 0.1 mm wide. |
2n | = 14. |
|
Boechera subpinnatifida |
Boechera duchesnensis |
|
Phenology | Flowering Mar–May. | Flowering May. |
Habitat | Rock outcrops, talus, gravelly soil, often in sagebrush-grassland communities | Sandy soil on rocky slopes, mostly in pinyon-juniper woodlands |
Elevation | 800-2400 m (2600-7900 ft) | 1300-1800 m (4300-5900 ft) |
Distribution |
CA; ID; NV; OR; UT
|
CO; NM; UT |
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.) |
Morphological and isozyme analyses indicate that Boechera duchesnensis is an apomictic species that arose through hybridization between B. formosa and B. pallidifolia (M. D. Windham and Allphin, unpubl.). It is easily distinguished from those species by having fruits that are glabrous proximally and sparsely pubescent distally. It shares this distinctive fruit pubescence with B. xylopoda, an apomictic hybrid between B. perennans and B. pulchra (see Windham and I. A. Al-Shehbaz 2007b for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 409. | FNA vol. 7, p. 375. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis subpinnatifida | Arabis pulchra var. duchesnensis, B. pulchra var. duchesnensis |
Name authority | (S. Watson) Al-Shehbaz: Novon 13: 389. (2003) | (Rollins) Windham: Harvard Pap. Bot. 12: 239. (2007) |
Web links |
|