Boechera quebecensis |
Boechera pusilla |
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Habit | Biennials or perennials; short-lived; apomictic; caudex present or absent. | Perennials; long-lived; (cespitose); 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 sessile, 2–4-rayed, 0.15–0.5 mm, glabrous distally. |
usually 2–6 per caudex branch, arising from margin of rosette near ground surface, 0.5–2 dm, glabrous or sparsely pubescent proximally, trichomes simple and short-stalked, 2-rayed, to 0.2 mm, glabrous distally. |
Basal leaves | blade oblanceolate, 5–15 mm wide, margins denticulate, ciliate proximally, trichomes (simple), to 1 mm, surfaces moderately pubescent, trichomes subsessile, (2- or) 3–7-rayed, 0.1–0.3 mm. |
blade linear-oblanceolate, 1–2.5 mm wide, margins entire, ciliate along petiole, trichomes (simple), 0.4–0.7 mm, surfaces usually sparsely pubescent, rarely glabrous, trichomes short-stalked, 2- or 3-rayed, 0.1–0.4 mm. |
Cauline leaves | 4–15, not concealing stem; blade auricles 1–3.5 mm, surfaces of distalmost leaves glabrous. |
3–5, not concealing stem; blade auricles 0–0.2 mm, surfaces of distalmost leaves usually glabrous or, rarely, margins sparsely ciliate. |
Racemes | 11–41-flowered, usually unbranched. |
6–13-flowered, unbranched. |
Flowers | divaricate at anthesis; sepals pubescent; petals white, 6–7 × 1–2 mm, glabrous; pollen spheroid. |
divaricate-ascending at anthesis; sepals glabrous or sparsely pubescent, trichomes spreading, 2-rayed; petals white to lavender, 4–5 × 1.5–1.8 mm, glabrous; pollen spheroid. |
Fruiting pedicels | horizontal to slightly descending, curved to straight, 3–8(–14) mm, glabrous or with some subappressed, branched trichomes. |
horizontal to divaricate-descending, straight or slightly curved downward, 2–5 mm, glabrous. |
Fruits | horizontal to slightly descending, not appressed to rachis, secund, straight, edges parallel, 3–6 cm × 1.5–2 mm; valves glabrous; ovules 56–94 per ovary. |
horizontal or divaricate-descending, not appressed to rachis, secund, straight, edges parallel, 1.6–3.2 cm × 1.5–2 mm; valves glabrous; ovules 20–32 per ovary; style 0.1–0.4 mm. |
Seeds | uniseriate, 1.2–1.5 × 1–1.3 mm; wing continuous, 0.1–0.15 mm wide. |
uniseriate, 1.2–1.5 × 0.8–0.9 mm; not winged or with distal wing 0.05–0.1 mm wide. |
Boechera quebecensis |
Boechera pusilla |
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Phenology | Flowering Jun–Jul. | Flowering May–Jun. |
Habitat | Calcareous rock outcrops and talus slopes | Cracks and crevices of granitic rock outcrops |
Elevation | 0-300 m (0-1000 ft) | 2400-2500 m (7900-8200 ft) |
Distribution |
QC |
WY |
Discussion | Morphological evidence suggests that Boechera quebecensis is an apomictic species that arose through hybridization between B. holboellii and B. stricta; it is most likely to be confused with B. grahamii (see M. D. Windham and I. A. Al-Shehbaz 2007b for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Morphological evidence suggests that Boechera pusilla is an apomictic species that arose through hybridization between B. lemmonii and B. pendulina; it is known only from the type locality in southwestern Wyoming. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 401. | FNA vol. 7, p. 400. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis divaricarpa var. dechamplainii | Arabis pusilla |
Name authority | Windham & Al-Shehbaz: Harvard Pap. Bot. 12: 246. (2007) | (Rollins) Dorn: Vasc. Pl. Wyoming ed. 3, 376. (2001) |
Web links |