Boechera tularensis |
Boechera yorkii |
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Tulare rockcress |
last chance rock cress |
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Habit | Biennials or perennials; short-lived; apomictic; caudex present or absent. | Perennials; long-lived; sexual; caudex woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 2–7 dm, sparsely to densely pubescent proximally, trichomes subsessile, sub-malpighiaceous, 0.3–0.6 mm, glabrous distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, 1–3 dm, densely pubescent proximally, trichomes short-stalked, 4–7-rayed, 0.1–0.5 mm, mixed proximally with simple and short- to long-stalked, 2- or 3-rayed ones, to 1.5 mm, moderately pubescent distally. |
Basal leaves | blade oblanceolate, 3–7 mm wide, margins entire, ciliate proximally, trichomes (simple), to 0.8 mm, surfaces sparsely to densely pubescent, trichomes subsessile, 2–5-rayed, 0.2–0.55 mm. |
blade linear-oblanceolate, 1.5–3 mm wide, margins entire, ciliate proximally, trichomes (simple and 2- or 3-rayed), to 1.5 mm, surfaces moderately pubescent, trichomes short-stalked, 4–7-rayed, 0.3–0.6 mm. |
Cauline leaves | 7–17, often concealing stem proximally; blade auricles 2–5 mm, surfaces of distalmost leaves sparsely pubescent or glabrous. |
9–17, concealing stem proximally; blade auricles absent, surfaces of distalmost leaves moderately pubescent. |
Racemes | 19–39-flowered, usually unbranched. |
8–35-flowered, usually unbranched. |
Flowers | divaricate to pendent at anthesis; sepals pubescent; petals white to pale lavender, 6–7 × 1.2–2 mm, glabrous; pollen spheroid. |
pendent at anthesis; sepals pubescent; petals yellowish proximally and brick-red distally or, rarely, one color throughout, 9–10 × 0.8–1 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | reflexed, recurved proximally, 5–13 mm, glabrous. |
reflexed, straight, 1.5–2 mm, pubescent, trichomes appressed, branched. |
Fruits | reflexed, rarely appressed to rachis, not secund, straight, edges parallel, 4–7(–8.5) cm × 2–2.3 mm; valves glabrous; ovules 88–104 per ovary; style 0.3–0.7 mm. |
(immature) reflexed, often appressed to rachis, not secund, straight, edges parallel, ca. 4 cm; valves pubescent throughout; style ca. 0.3 mm. |
Seeds | sub-biseriate, 2–2.5 × 1.1–1.5 mm; wing continuous, 0.15–0.25 mm wide. |
not seen. |
Boechera tularensis |
Boechera yorkii |
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Phenology | Flowering Jun–Jul. | Flowering May. |
Habitat | Rocky slopes in montane and subalpine habitats | Crevices and ledges of calcareous rock outcrops |
Elevation | 2400-3200 m (7900-10500 ft) | 2200-2400 m (7200-7900 ft) |
Distribution |
CA |
CA |
Discussion | Morphological evidence suggests that Boechera tularensis is an apomictic species that contains three different genomes, one each from B. rectissima, B. retrofracta, and B. stricta. It is most often confused with B. pinetorum and B. retrofracta, but is easily distinguishable from both (see M. D. Windham and I. A. Al-Shehbaz 2007b for detailed comparison). It is known from the southern Sierra Nevada (Fresno and Tulare counties). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera yorkii is immediately recognizable by its yellowish to brick-red petals and extremely short (1.5–2 mm), reflexed fruiting pedicels. It is known only from Last Chance Mountains in Inyo County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 410. | FNA vol. 7, p. 412. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Windham & Al-Shehbaz: Harvard Pap. Bot. 12: 249. (2007) | S. Boyd: Madroño 51: 387, figs. 1–3. (2004) |
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