Boechera paupercula |
Boechera depauperata |
|
---|---|---|
boechera paupercula, littleleaf rockcress, small-flower rock-cress, tiny suncress |
soldier rockcress |
|
Habit | Perennials; long-lived; (cespitose); sexual; caudex often woody. | Perennials; usually long-lived; (cespitose); 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 near ground surface, 0.5–1.5(–2) dm, densely pubescent proximally, trichomes short-stalked, 4–8-rayed, 0.07–0.4 mm, usually sparsely pubescent distally, rarely glabrous. |
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 narrowly oblanceolate, 0.7–3(–5) mm wide, margins entire, sometimes ciliate proximally, trichomes to 0.4 mm, surfaces densely pubescent, trichomes short-stalked, 5–8-rayed, 0.05–0.25 mm. |
Cauline leaves | 2–6, rarely concealing stem; blade auricles 0 (or 0.2–1.5) mm, surfaces of distalmost leaves glabrous. |
3–7, not concealing stem; blade auricles 0.5–1.5 mm, surfaces of distalmost leaves usually pubescent, rarely glabrous. |
Racemes | 3–8-flowered, unbranched. |
9–23-flowered, 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 lavender to purplish, 3.5–5 × 0.8–1.2 mm, glabrous; pollen spheroid. |
Fruiting pedicels | erect, straight, 3–9 mm, glabrous or sparsely pubescent. |
divaricate-ascending, straight, 1.5–7 mm, usually pubescent, rarely glabrous, trichomes appressed, branched. |
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. |
divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 1.7–3.5(–4.5) cm × 1–1.5 mm; valves glabrous; ovules 32–44 per ovary; style 0.05–0.2 mm. |
Seeds | usually uniseriate, rarely sub-biseriate, 1.5–2(–2.5) × 1–1.4 mm; wing continuous, 0.3–1 mm wide. |
uniseriate, 1.2–1.5 × 1–1.2 mm; wing continuous, 0.1–0.15 mm wide. |
Boechera paupercula |
Boechera depauperata |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Jul. |
Habitat | Rock outcrops, talus slopes, gravelly soil in alpine and subalpine habitats | Exposed ridges and talus slopes in subalpine and alpine habitats |
Elevation | 2400-3400 m (7900-11200 ft) | 2700-3900 m (8900-12800 ft) |
Distribution |
CA; ID; OR; WA; WY
|
CA; NV
|
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 depauperata is an apomictic species that arose through hybridization between B. lemmonii and B. paupercula (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). It is known in California from Fresno, Mono, and Tulare counties and in Nevada from Washoe County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 394. | FNA vol. 7, p. 373. |
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 depauperata, Arabis lemmonii var. depauperata |
Name authority | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 75. (2006) | (A. Nelson & P. B. Kennedy) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 262. (2007) |
Web links |
|
|