Boechera paupercula |
Boechera californica |
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boechera paupercula, littleleaf rockcress, small-flower rock-cress, tiny suncress |
California rockcress |
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Habit | Perennials; long-lived; (cespitose); sexual; caudex often woody. | Perennials; usually long-lived; apomictic; caudex 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 1 per caudex branch, arising from center of rosette, elevated above ground surface on woody base, (2–)3.5–13 dm, densely pubescent proximally, trichomes short-stalked, 2–4-rayed, 0.3–0.9 mm, moderately to sparsely 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 linear to oblanceolate, 3–10(–13) mm wide, margins entire or denticulate, ciliate along petiole, trichomes to 1.3 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.2–0.5 mm. |
Cauline leaves | 2–6, rarely concealing stem; blade auricles 0 (or 0.2–1.5) mm, surfaces of distalmost leaves glabrous. |
12–35(–55), often concealing stem proximally; blade auricles 1–5(–6) mm, surfaces of distalmost leaves pubescent. |
Racemes | 3–8-flowered, unbranched. |
30–120-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. |
divaricate-ascending at anthesis; sepals pubescent; petals usually purple, rarely pinkish, 9–14 × 1.5–3 mm, glabrous or sparsely pubescent (trichomes scattered abaxially); pollen spheroid. |
Fruiting pedicels | erect, straight, 3–9 mm, glabrous or sparsely pubescent. |
descending to horizontal, usually recurved, rarely straight, 4–20 mm, pubescent, trichomes appressed, 3–7-rayed. |
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. |
widely pendent, not appressed to rachis, not secund, usually curved, rarely straight, edges parallel, (6–)8–12 cm × 1.5–2.5 mm; valves glabrous or trichomes sometimes scattered; ovules 140–180 per ovary; style 0.05–0.3 mm. |
Seeds | usually uniseriate, rarely sub-biseriate, 1.5–2(–2.5) × 1–1.4 mm; wing continuous, 0.3–1 mm wide. |
uniseriate or sub-biseriate, 1.7–2 × 1.2–1.7 mm; wing continuous, 0.2–0.4 mm wide. |
Boechera paupercula |
Boechera californica |
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Phenology | Flowering Jun–Aug. | Flowering Mar–Jun. |
Habitat | Rock outcrops, talus slopes, gravelly soil in alpine and subalpine habitats | Rocky slopes and gravelly soil in desert chaparral and oak woodlands |
Elevation | 2400-3400 m (7900-11200 ft) | 300-2300 m (1000-7500 ft) |
Distribution |
CA; ID; OR; WA; WY
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CA; Mexico (Baja California)
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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.) |
Morphological evidence suggests that Boechera californica is an apomictic species that arose through hybridization between B. arcuata and B. pulchra (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). In the flora area, B. californica is known only from Los Angeles, Riverside, San Bernardino, and San Diego counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 394. | FNA vol. 7, p. 369. |
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 sparsiflora var. californica |
Name authority | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 75. (2006) | (Rollins) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 260. (2007) |
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