Boechera rollinsiorum |
Boechera fernaldiana |
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Habit | Perennials; long-lived; sexual; caudex woody. | Perennials; long-lived; (cespitose); sexual; caudex somewhat woody (sometimes with persistent, crowded leaf bases). | ||||
Stems | usually 3–5 per caudex branch, arising from margin of rosette, elevated above ground surface on woody base, 1–2.5 dm, densely pubescent proximally, trichomes short-stalked, 2–4 (or 5)-rayed, 0.2–0.4 mm, moderately to sparsely pubescent distally. |
usually 1 per caudex branch, arising from center of rosette, near ground surface or slightly elevated on woody base, 1–3.8 dm, densely pubescent proximally, trichomes short-stalked, 4–8-rayed, 0.04–0.1 mm, sometimes mixed with stalked, 2-rayed ones, to 0.5 mm, usually sparsely pubescent distally. |
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Basal leaves | blade oblanceolate, 3–5 mm wide, margins entire, ciliate proximally, trichomes (simple), to 0.6 mm, surfaces densely pubescent, trichomes short-stalked, 2–4 (or 5)-rayed, 0.15–0.4 mm. |
blade narrowly oblanceolate, 1–4 mm wide, margins entire, ciliate along petiole, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.04–0.1 mm. |
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Cauline leaves | 5–9, not concealing stem; blade auricles 0.5–1 mm, surfaces of distalmost leaves sparsely to moderately pubescent. |
5–10, not concealing stem; blade auricles 0.3–2 mm, surfaces of distalmost leaves usually sparsely pubescent. |
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Racemes | 5–11-flowered, usually unbranched. |
10–20-flowered, usually unbranched. |
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Flowers | divaricate-ascending at anthesis; sepals pubescent; petals pale purple, 6–8 × 1.5–2 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals (purplish or greenish) glabrous or sparsely or moderately pubescent; petals white or purple to lavender, 7–12 × 1.5–4 mm, glabrous; pollen ellipsoid. |
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Fruiting pedicels | descending, straight to slightly recurved, 4–6 mm, pubescent, trichomes appressed, branched. |
divaricate-ascending, straight, 5–20 mm, sparsely pubescent, trichomes appressed, branched. |
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Fruits | (immature) pendent, not appressed to rachis, not secund, straight, edges parallel; valves glabrous. |
divaricate-ascending, not appressed to rachis, not secund, straight or curved, edges parallel, 3.5–6.5(–7.5) cm × 1–1.6 mm; valves glabrous; ovules 30–72 per ovary; style 0.1–1 mm. |
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Seeds | not seen. |
uniseriate, 1–1.2 × 0.8–1 mm; wing continuous, ca. 0.1 mm wide. |
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Boechera rollinsiorum |
Boechera fernaldiana |
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Phenology | Flowering Jun. | |||||
Habitat | Metamorphosed igneous gravel on steep slopes | |||||
Elevation | ca. 2100 m (ca. 6900 ft) | |||||
Distribution |
ID |
CO; NV; UT |
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Discussion | Boechera rollinsiorum shows superficial similarities to both B. glareosa and B. lasiocarpa (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). It is known thus far only from the type collection below Galena Summit in central Idaho. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Subspecies 2 (2 in the flora). Taxa treated here as subspecies of Boechera fernaldiana share many morphological traits, and most recent authors (R. C. Rollins 1993; N. H. Holmgren 2005b) did not recognize them as distinct. They are consistently separated by the characters listed below, show some degree of molecular divergence (C. D. Bailey et al., unpubl.), and their ranges are separated by ca. 500 km. They clearly represent genetically isolated population systems that warrant taxonomic recognition. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 7, p. 403. | FNA vol. 7, p. 378. | ||||
Parent taxa | ||||||
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Synonyms | Arabis fernaldiana, Arabis canescens var. stylosa, Arabis fernaldiana var. stylosa | |||||
Name authority | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 81. (2006) | (Rollins) W. A. Weber: Phytologia 51: 370. (1982) | ||||
Web links |