Boechera sparsiflora |
Boechera bodiensis |
|
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elegant rockcress, sickle-pod rock-cress, slender rockcress, stretching suncress |
Bodie Hills rock cress |
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Habit | Biennials or perennials; short-lived; sexual; caudex present or absent. | Perennials; long-lived; (cespitose); apomictic; caudex somewhat woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 3–8 dm, densely pubescent proximally, trichomes simple mixed with fewer short-stalked, 2-rayed ones, 0.4–1.5 mm, glabrous or sparsely pubescent distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, 1.5–3.5 dm, densely pubescent proximally, trichomes short-stalked, 5–10-rayed, to 0.7 mm, sparsely pubescent or glabrous distally. |
Basal leaves | blade oblanceolate or linear-oblanceolate, 3–12 mm wide, margins usually entire, rarely dentate, ciliate proximally, trichomes (usually simple), to 1 mm, surfaces densely pubescent, trichomes short-stalked, 2–5-rayed, 0.3–0.8 mm. |
blade narrowly oblanceolate, 1–3 mm wide, margins entire, ciliate proximally, trichomes to 0.7 mm, surfaces densely pubescent, trichomes short-stalked, 5–10-rayed, 0.08–0.25 mm. |
Cauline leaves | (9–)15–35, often concealing stem proximally; blade auricles 3–10 mm, surfaces of distalmost leaves glabrous, sometimes margins ciliate. |
4–9, not concealing stem; blade auricles 0.5–2 mm, surfaces of distalmost leaves pubescent. |
Racemes | 12–50-flowered, usually unbranched. |
8–25-flowered, usually unbranched. |
Flowers | ascending at anthesis; sepals sparsely pubescent; petals usually lavender to purple, rarely white, 7–13 × 2–5 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals pubescent; petals lavender to purple, 4–5 × ca. 1 mm, glabrous; pollen spheroid. |
Fruiting pedicels | usually ascending, rarely almost horizontal, straight or slightly recurved, 3–10(–18) mm, usually pubescent, rarely glabrous, trichomes spreading, usually simple. |
ascending to divaricate-ascending, straight, 3–7 mm, pubescent, trichomes appressed, branched. |
Fruits | usually ascending, rarely almost horizontal, not appressed to rachis, not secund, usually curved, edges parallel, 5–13 cm × 1.7–2 mm; valves glabrous; ovules 90–170 per ovary; style 0.05–0.3 mm. |
divaricate-ascending, not appressed to rachis, not secund, straight or curved, edges parallel, 4–6.2 cm × 1.2–1.8 mm; valves glabrous; ovules 48–68 per ovary; style 0.1–0.2 mm. |
Seeds | uniseriate, 1.5–2 × 1–1.5 mm; wing continuous, 0.1–0.2 mm wide. |
uniseriate, 1–1.5 × 0.8–1.2 mm; wing continuous, 0.1–0.15 mm wide. |
2n | = 14. |
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Boechera sparsiflora |
Boechera bodiensis |
|
Phenology | Flowering Apr–Jun. | Flowering Jul–Aug. |
Habitat | Rocky slopes, clay hills, sandy soil in sagebrush and mountain shrub communities, meadows, and open conifer forests | Loose soil, crevices of igneous rock |
Elevation | 400-2800 m (1300-9200 ft) | 2400-2900 m (7900-9500 ft) |
Distribution |
CA; ID; NV; OR; UT; WA; BC
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CA; NV |
Discussion | As circumscribed by R. C. Rollins (1993), Boechera sparsiflora included six varieties encompassing three sexual diploids and a number of apomictic hybrids. The most distinctive of those elements are recognized here as the separate species B. arcuata, B. atrorubens, B. californica, and B. pauciflora. The narrow circumscription of B. sparsiflora adopted here includes only sexual diploids. It is distinguished from other taxa previously assigned to it by having proximal stems densely pubescent with predominantly simple (some 2-rayed) trichomes to 1.5 mm, usually glabrous distal stems, and ascending fruiting pedicels with spreading, usually simple trichomes (rarely glabrous). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. In his original description, Rollins suggested that Boechera bodiensis is closely related to B. cobrensis and B. falcifructa. Subsequent studies (M. D. Windham and I. A. Al-Shehbaz, unpubl.) indicate that both B. bodiensis and B. falcifructa are apomictic hybrids containing one or more genomes derived from B. cobrensis. In the case of B. falcifructa, the second parent is clearly B. fernaldiana, but the second parent of B. bodiensis remains uncertain. Boechera bodiensis is most similar to B. falcifructa. The latter differs by having gently recurved fruiting pedicels 6–12 mm, 62–80 ovules per ovary, and pendulous fruits; it is known from Elko and Lander counties, Nevada. By contrast, B. bodiensis has straight fruiting pedicels 3–7 mm long, divaricate-ascending fruits, 48–68 ovules per ovary, and is known from Mono County, California, and Lyon and Mineral counties, Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 407. | FNA vol. 7, p. 367. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis sparsiflora, Arabis arcoidea, Arabis campyloloba, Arabis peramoena, Arabis polytricha, Arabis sparsiflora var. peramoena | Arabis bodiensis |
Name authority | (Nuttall) Dorn: Vasc. Pl. Wyoming ed. 3, 376. (2001) | (Rollins) Al-Shehbaz: Novon 13: 384. (2003) |
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