Boechera consanguinea |
Boechera evadens |
|
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Four Corners rockcress |
hidden rockcress |
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Habit | Biennials or perennials; short-lived; apomictic; caudex present or absent. | Perennials; long-lived; (cespitose); sexual; caudex woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 1.5–5 dm, densely pubescent proximally, trichomes short-stalked, 2–6-rayed, 0.2–0.5 mm, glabrous or sparsely pubescent distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, 1–2.5 dm, densely pubescent proximally, trichomes short-stalked, 2–5-rayed, 0.2–0.6 mm, and sparse, simple ones to 1 mm, glabrous distally. |
Basal leaves | blade oblanceolate, 2–10 mm wide, margins usually dentate, sometimes ciliate near petiole base, trichomes (usually spurred), to 0.7 mm, surfaces moderately to densely pubescent, trichomes short-stalked, 4–8-rayed, 0.1–0.4 mm. |
blade narrowly oblanceolate, 1.5–3 mm wide, margins entire, ciliate along petiole, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.1–0.2 mm. |
Cauline leaves | 15–36, sometimes concealing stem proximally; blade auricles 1–3 mm, surfaces of distalmost leaves sparsely pubescent. |
3–5, not concealing stem; blade auricles 0.5–1 mm, surfaces of distalmost leaves pubescent. |
Racemes | 20–55-flowered, usually unbranched. |
10–22-flowered, unbranched. |
Flowers | divaricate-descending at anthesis; sepals pubescent; petals pale lavender, 5–8.5 × 1–2 mm, glabrous; pollen spheroid. |
ascending at anthesis; sepals pubescent; petals white, 3–4 × 0.5–0.8 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | reflexed to divaricate-descending, usually curved downward, 8–14 mm, usually pubescent, rarely glabrous, trichomes subappressed, branched. |
divaricate-ascending, straight, 4–8 mm, sparsely pubescent, trichomes appressed, branched. |
Fruits | reflexed to pendent, rarely appressed to rachis, not secund, straight or slightly curved, edges parallel, 4–6 cm × 1–2 mm; valves glabrous; ovules 100–128 per ovary; style 0.05–0.5 mm. |
divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 3–4 cm × 1.2–1.5 mm; valves glabrous; ovules 46–52 per ovary; style ca. 0.1 mm. |
Seeds | biseriate to sub-biseriate, mature seeds not seen. |
uniseriate, 1–1.1 × 0.9–1 mm; wing continuous, ca. 0.1 mm wide. |
Boechera consanguinea |
Boechera evadens |
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Phenology | Flowering May. | Flowering Jun. |
Habitat | Rocky slopes and sandy soil in ponderosa pine, pinyon-juniper, and sagebrush communities | Rock outcrops |
Elevation | 1900-2500 m (6200-8200 ft) | ca. 2600 m (ca. 8500 ft) |
Distribution |
CO; NM; UT
|
CA |
Discussion | Morphological evidence suggests that Boechera consanguinea is an apomictic species that arose through hybridization between B. fendleri and B. retrofracta. It is most similar to B. goodrichii, another apomictic hybrid involving B. retrofracta (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera evadens is a sexual taxon that was originally interpreted as a disjunct population of Arabis (Boechera) fernaldiana, but is easily distinguished from that species by having much shorter (3–4 versus 7–12 mm) petals, larger (0.2–0.6 versus 0.04–0.1 mm) trichomes proximally on stems, and shorter (3–4 versus 4–7.5 cm) fruits (see M. D. Windham and I. A. Al-Shehbaz 2006 for additional distinctions). It is known only from the holotype specimen collected near Sherman Pass in Tulare County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 371. | FNA vol. 7, p. 376. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis consanguinea, Arabis holboellii var. consanguinea | |
Name authority | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 261. (2007) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 66. (2006) |
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