Boechera harrisonii |
Boechera consanguinea |
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Four Corners rockcress |
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Habit | Perennials; long-lived; (some-what cespitose); apomictic; caudex often woody. | Biennials or perennials; short-lived; apomictic; caudex present or absent. |
Stems | 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. |
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. |
Basal leaves | 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. |
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. |
Cauline leaves | 3–7, not concealing stem; blade auricles 0.5–1.5 mm, surfaces of distalmost leaves glabrous. |
15–36, sometimes concealing stem proximally; blade auricles 1–3 mm, surfaces of distalmost leaves sparsely pubescent. |
Racemes | 5–12-flowered, usually unbranched. |
20–55-flowered, usually unbranched. |
Flowers | ascending at anthesis; sepals pubescent; petals lavender, 5–7.5 × 0.8–1.5 mm, glabrous; pollen spheroid. |
divaricate-descending at anthesis; sepals pubescent; petals pale lavender, 5–8.5 × 1–2 mm, glabrous; pollen spheroid. |
Fruiting pedicels | divaricate-ascending, straight, 8–12 mm, glabrous. |
reflexed to divaricate-descending, usually curved downward, 8–14 mm, usually pubescent, rarely glabrous, trichomes subappressed, branched. |
Fruits | 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. |
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. |
Seeds | uniseriate, 1.1–1.3 × 0.8–1.1 mm; wing continuous, 0.08–0.1 mm wide. |
biseriate to sub-biseriate, mature seeds not seen. |
Boechera harrisonii |
Boechera consanguinea |
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Phenology | Flowering May–Jun. | Flowering May. |
Habitat | Limestone and quartzite cliffs | Rocky slopes and sandy soil in ponderosa pine, pinyon-juniper, and sagebrush communities |
Elevation | 1500-1600 m (4900-5200 ft) | 1900-2500 m (6200-8200 ft) |
Distribution |
UT |
CO; NM; UT
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Discussion | 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.) |
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.) |
Source | FNA vol. 7, p. 383. | FNA vol. 7, p. 371. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis harrisonii, B. microphylla var. harrisonii | Arabis consanguinea, Arabis holboellii var. consanguinea |
Name authority | (S. L. Welsh) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 266. (2007) | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 261. (2007) |
Web links |