Boechera spatifolia |
Boechera villosa |
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spoonleaf rockcress |
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Habit | Perennials; short- to long-lived; sexual; caudex usually not woody (rarely with persistent, crowded leaf bases). | Perennials; short-lived; sexual; caudex not woody. |
Stems | simple or few to several per caudex branch, arising from center of rosette near ground surface, 1.5–3.5(–5) dm, densely pubescent proximally, trichomes simple mixed with short-stalked ones, 2-rayed, 0.3–0.7 mm. |
1–3 per caudex branch, arising laterally proximal to sterile shoots near ground surface, ca. 2.5 dm, densely pubescent proximally, trichomes simple and 2-rayed, 0.25–0.7 mm, glabrescent distally. |
Basal leaves | blade narrowly oblanceolate, 1.5–3(–4) mm wide, margins entire, strongly ciliate at least along petiole, trichomes (simple), to 1 mm, surfaces glabrous or sparsely pubescent, trichomes simple and short-stalked, 2-rayed, 0.3–0.7 mm. |
blade oblanceolate to obovate, 2.5–5 mm wide, margins entire, ciliate along petiole, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes simple and short-stalked, 2- or 3-rayed, 0.25–0.5 mm. |
Cauline leaves | 5–15(–20), often concealing stem proximally; blade auricles 0.5–1.5 mm, surfaces of distalmost leaves usually glabrous. |
4–6, not concealing stem; blade auricles ca. 1 mm, surfaces of distalmost leaves sparsely pubescent. |
Racemes | 10–30-flowered, usually unbranched. |
6–10-flowered, unbranched. |
Flowers | divaricate-ascending at anthesis; sepals pubescent; petals usually white, rarely pale lavender, 3–3.7(–4) × 0.5–0.8 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals pubescent; petals lavender, 4–5 × 1–1.5 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | horizontal or slightly descending, curved or angled downward, 6–10(–15) mm, usually glabrous, rarely sparsely pubescent, trichomes spreading, simple. |
ascending, straight, 6–10 mm, glabrous or sparsely pubescent, trichomes subappressed, branched. |
Fruits | pendent, not appressed to rachis, rarely slightly secund, straight or gently curved, edges parallel, 3.3–5.7 cm × 1.2–1.8 mm; valves glabrous; ovules 90–126 per ovary; style 0.1–0.4 mm. |
divaricate-ascending, not appressed to rachis, not secund, slightly curved, edges parallel, 4–5 cm × ca. 1 mm; valves glabrous; ovules ca. 64 per ovary; style ca. 0.2 mm. |
Seeds | biseriate, 0.7–0.9 × 0.5–0.6 mm; wing distal or, sometimes, absent, 0.05–0.1 mm wide. |
uniseriate, (none mature). |
2n | = 14. |
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Boechera spatifolia |
Boechera villosa |
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Phenology | Flowering May–Aug. | Flowering May. |
Habitat | Rocky slopes and gravelly soil in sagebrush, pinyon-juniper woodlands, open conifer forests and subalpine meadows | Basalt outcrop in pinyon-juniper woodlands |
Elevation | 1800-2800 m (5900-9200 ft) | ca. 2100 m (ca. 6900 ft) |
Distribution |
CO; NM
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NM |
Discussion | Boechera spatifolia is a sexual diploid that usually has been treated as a variety of Arabis (Boechera) fendleri but appears to be sufficiently distinct to warrant recognition at species level (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). There is little geographic overlap between the two, with B. spatifolia confined to the mountains of central Colorado and north-central New Mexico and B. fendleri ranging from western New Mexico and the Four Corners region through northern Arizona to southern Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera villosa is known only from the type collection from the Rio Grande Gorge in Taos County. The holotype was originally identified as Arabis (Boechera) perennans but clearly is more closely related to B. pallidifolia (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 408. | FNA vol. 7, p. 411. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis spatifolia, Arabis fendleri var. spatifolia, B. fendleri subsp. spatifolia, B. fendleri var. spatifolia | |
Name authority | (Rydberg) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 84. (2006) | Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 86. (2006) |
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