Boechera paupercula |
Boechera perstellata |
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boechera paupercula, littleleaf rockcress, small-flower rock-cress, tiny suncress |
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Habit | Perennials; long-lived; (cespitose); sexual; caudex often woody. | Perennials; usually short-lived; sexual; caudex not woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 0.3–1.5 dm, densely pubescent proximally, trichomes simple and short-stalked, 2–4-rayed, (0.07–)0.1–0.2 mm, glabrous or sparsely pubescent distally. |
usually 2–5 per plant, arising from margin of rosette near ground surface, (1–)2–8 dm, densely pubescent proximally, trichomes short-stalked, 3- or 4-rayed, 0.1–0.5 mm, similarly pubescent distally. |
Basal leaves | blade linear-oblanceolate, 1–3(–5) mm wide, margins entire, ciliate proximally, trichomes to 0.4 mm, surfaces densely pubescent, trichomes short-stalked, 2–6-rayed, (0.07–)0.1–0.2 mm. |
blade obovate to oblanceolate, (5–)10–45 mm wide, margins usually coarsely dentate, rarely sinuate, ciliate on petiole base, surfaces moderately pubescent, trichomes short-stalked, 3- or 4(–6)-rayed, 0.1–0.5 mm. |
Cauline leaves | 2–6, rarely concealing stem; blade auricles 0 (or 0.2–1.5) mm, surfaces of distalmost leaves glabrous. |
6–25, concealing stem proximally; blade auricles 1–6 mm, surfaces of distalmost leaves pubescent. |
Racemes | 3–8-flowered, unbranched. |
10–40-flowered, usually unbranched. |
Flowers | erect at anthesis; sepals glabrous or sparsely pubescent; petals lavender to purplish, 4–6(–7) × 1–2 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals pubescent; petals purplish, 3–4 × 0.7–1 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | erect, straight, 3–9 mm, glabrous or sparsely pubescent. |
usually horizontal, usually straight, rarely slightly curved, 5–15 mm, pubescent, trichomes spreading, simple. |
Fruits | erect, appressed to rachis, not secund, straight, edges parallel, 2.5–5.5 cm × 1.3–1.7(–2) mm; valves glabrous; ovules 24–40 per ovary; style 0.2–1 mm. |
usually horizontal, not appressed to rachis, not secund, straight, edges parallel, (1.5–)2–3.3 cm × 0.8–1 mm; valves sparsely pubescent throughout; ovules 12–20 per ovary; style 0.4–0.8 mm. |
Seeds | usually uniseriate, rarely sub-biseriate, 1.5–2(–2.5) × 1–1.4 mm; wing continuous, 0.3–1 mm wide. |
uniseriate, 0.8–1.1 × 0.6–0.8 mm, not winged. |
2n | = 14. |
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Boechera paupercula |
Boechera perstellata |
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Phenology | Flowering Jun–Aug. | Flowering Apr–May. |
Habitat | Rock outcrops, talus slopes, gravelly soil in alpine and subalpine habitats | Calcareous bluffs and wooded hillsides |
Elevation | 2400-3400 m (7900-11200 ft) | 200-400 m (700-1300 ft) |
Distribution |
CA; ID; OR; WA; WY
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KY; TN |
Discussion | Boechera paupercula is usually subsumed under Arabis (Boechera) lyallii but is amply distinct (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Boechera perstellata is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 394. | FNA vol. 7, p. 396. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis paupercula, Arabis lyallii var. nubigena, Arabis microphylla var. nubigena, Arabis nubigena | Arabis perstellata, Arabis perstellata var. ampla |
Name authority | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 75. (2006) | (E. L. Braun) Al-Shehbaz: Novon 13: 388. (2003) |
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