Boechera glaucovalvula |
Boechera rigidissima |
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bluepod rockcress |
Trinity Mountain rockcress |
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Habit | Perennials; short- to long-lived; sexual; caudex usually not woody. | Perennials; long-lived; apomictic; caudex woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, (0.6–)1–4.5 dm, densely pubescent proximally, trichomes short-stalked, 4–8-rayed, 0.1–0.4 mm, similarly pubescent distally. |
usually 1 per caudex branch, arising from center of rosette, slightly elevated on woody base or from near ground surface, 2–6 dm, pubescent proximally, trichomes usually subsessile, 2- or 3-rayed, rarely simple, 0.25–0.4 mm, glabrous distally. |
Basal leaves | blade linear to linear-oblanceolate, 2–4(–6) mm wide, margins entire, usually ciliate at petiole base, trichomes (simple or spurred), to 1.5 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.1–0.4 mm. |
blade oblanceolate, 2–6 mm wide, margins entire, ciliate proximally, trichomes to 0.7 mm, surfaces sparsely pubescent, trichomes subsessile to short-stalked, 2–5-rayed, 0.1–0.4 mm. |
Cauline leaves | 6–10, not concealing stem; blade auricles absent, surfaces of distalmost leaves densely pubescent. |
5–10, rarely concealing stem proximally; blade auricles 0.5–2 mm, surfaces of distalmost leaves glabrous. |
Racemes | (5–)10–25-flowered, usually unbranched. |
5–16-flowered, usually unbranched. |
Flowers | divaricate at anthesis; sepals pubescent; petals light purple to lavender, 6–9 × 1.5–2.5 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals glabrous; petals purple, 6–8 × 1.5–2 mm, glabrous; pollen spheroid. |
Fruiting pedicels | reflexed, strongly curved at base, 2–10 mm, pubescent, trichomes appressed, branched. |
divaricate-ascending, straight, 4–10 mm, glabrous. |
Fruits | strongly reflexed, sometimes appressed to rachis, often secund, straight, edges parallel, (1.8–)2.5–4.5 cm × 5–8 mm; valves glabrous; ovules 24–62 per ovary; style 0.2–0.6 mm. |
divaricate-ascending, not appressed to rachis, not secund, straight, edges somewhat undulate (not parallel), 4–6.5(–7.6) cm × 2.5–3.5 mm; valves glabrous; ovules 24–54 per ovary; style 0.2–0.8 mm. |
Seeds | biseriate, 5–6 × 4–5 mm; wing continuous, 1.8–2.5 mm wide. |
uniseriate, 2.5–3.2 × 1.8–2.5 mm; wing distal, 0.3–1 mm wide. |
2n | = 14. |
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Boechera glaucovalvula |
Boechera rigidissima |
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Phenology | Flowering Mar–Apr. | Flowering Jul–Aug. |
Habitat | Rocky slopes and gravelly soil, usually under shelter of desert shrubs | Rocky places in open conifer forests |
Elevation | 600-1600 m (2000-5200 ft) | 1800-2000 m (5900-6600 ft) |
Distribution |
CA; NV
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CA; NV |
Discussion | Boechera glaucovalvula, a distinctive sexual diploid that has the widest fruits in the genus, is known from Inyo, Mono, Riverside, and San Bernardino counties, California, and Clark and Nye counties, Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Plants assigned to Boechera rigidissima appear to represent a series of apomictic hybrids, possibly involving B. stricta and B. suffrutescens. The two varieties recognized by Rollins are well isolated geographically (in Trinity County, California, and Washoe County, Nevada, respectively) and show enough morphological divergence to suggest that they represent distinct origins, if not different combinations of parental genomes. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 380. | FNA vol. 7, p. 403. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis glaucovalvula | Arabis rigidissima, Arabis rigidissima var. demota |
Name authority | (M. E. Jones) Al-Shehbaz: Novon 13: 385. (2003) | (Rollins) Al-Shehbaz: Novon 13: 389. (2003) |
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