Boechera consanguinea |
Boechera harrisonii |
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Four Corners rockcress |
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Habit | Biennials or perennials; short-lived; apomictic; caudex present or absent. | Perennials; long-lived; (some-what cespitose); apomictic; caudex often 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 3–7 per caudex branch, arising from margin of rosette near ground surface, 0.5–2.5 dm, usually sparsely pubescent proximally, rarely glabrous, trichomes short-stalked, 2- or 3-rayed, 0.06–0.2 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, 2–4 mm wide, margins entire or somewhat dentate, ciliate near petiole base, trichomes (simple), to 0.5 mm, surfaces sparsely pubescent, trichomes short-stalked, 2–5-rayed, 0.1–0.25 mm. |
Cauline leaves | 15–36, sometimes concealing stem proximally; blade auricles 1–3 mm, surfaces of distalmost leaves sparsely pubescent. |
3–7, not concealing stem; blade auricles 0.5–1.5 mm, surfaces of distalmost leaves glabrous. |
Racemes | 20–55-flowered, usually unbranched. |
5–12-flowered, usually 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 lavender, 5–7.5 × 0.8–1.5 mm, glabrous; pollen spheroid. |
Fruiting pedicels | reflexed to divaricate-descending, usually curved downward, 8–14 mm, usually pubescent, rarely glabrous, trichomes subappressed, branched. |
divaricate-ascending, straight, 8–12 mm, glabrous. |
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. |
usually divaricate-ascending, rarely nearly horizontal, not appressed to rachis, not secund, curved to straight, edges parallel, 3–4.7 cm × 1–1.5 mm; valves glabrous; ovules 64–86 per ovary; style 0.2–0.5 mm. |
Seeds | biseriate to sub-biseriate, mature seeds not seen. |
uniseriate, 1.1–1.3 × 0.8–1.1 mm; wing continuous, 0.08–0.1 mm wide. |
Boechera consanguinea |
Boechera harrisonii |
|
Phenology | Flowering May. | Flowering May–Jun. |
Habitat | Rocky slopes and sandy soil in ponderosa pine, pinyon-juniper, and sagebrush communities | Limestone and quartzite cliffs |
Elevation | 1900-2500 m (6200-8200 ft) | 1500-1600 m (4900-5200 ft) |
Distribution |
CO; NM; UT
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UT |
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.) |
Morphological evidence suggests that Boechera harrisonii is an apomictic species that arose through hybridization between B. microphylla and B. perennans (see M. D. Windham and I. A. Al-Shehbaz 2007 for detailed comparison). Boechera harrisonii is known only from Utah and Wasatch counties in north-central Utah. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 371. | FNA vol. 7, p. 383. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis consanguinea, Arabis holboellii var. consanguinea | Arabis harrisonii, B. microphylla var. harrisonii |
Name authority | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 261. (2007) | (S. L. Welsh) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 266. (2007) |
Web links |