Boechera harrisonii |
Boechera glareosa |
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Habit | Perennials; long-lived; (some-what cespitose); apomictic; caudex often woody. | Perennials; short- to long-lived; sexual; caudex usually not woody. |
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 2–6 per caudex branch, arising from margin of rosette near ground surface, 0.8–4 dm, densely pubescent proximally, trichomes simple and short-stalked, 2-rayed, 0.3–0.6 mm, glabrous 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 narrowly oblanceolate, 1–5 mm wide, margins entire or few-toothed, ciliate proximally, trichomes (simple), to 0.9 mm, surfaces densely pubescent, trichomes simple and short-stalked, 2- or 3-rayed, 0.3–0.5 mm. |
Cauline leaves | 3–7, not concealing stem; blade auricles 0.5–1.5 mm, surfaces of distalmost leaves glabrous. |
3–6, not concealing stem; blade auricles 0.3–0.6 mm, surfaces of distalmost leaves glabrous. |
Racemes | 5–12-flowered, usually unbranched. |
7–15-flowered, usually unbranched. |
Flowers | ascending at anthesis; sepals pubescent; petals lavender, 5–7.5 × 0.8–1.5 mm, glabrous; pollen spheroid. |
ascending at anthesis; sepals pubescent; petals lavender, 3.5–6 × 1–1.5 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | divaricate-ascending, straight, 8–12 mm, glabrous. |
divaricate-ascending to horizontal, straight or gently recurved, 4–10 mm, glabrous or sparsely pubescent, trichomes spreading. |
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. |
divaricate-ascending to horizontal, not appressed to rachis, not secund, usually curved or straight, edges parallel, 2.5–4 cm × 1.2–1.5 mm; valves glabrous; ovules 50–80 per ovary; style 0.05–0.3 mm. |
Seeds | uniseriate, 1.1–1.3 × 0.8–1.1 mm; wing continuous, 0.08–0.1 mm wide. |
uniseriate, 1–1.5 × 0.7–1 mm; wing usually distal, ca. 0.1 mm wide. |
Boechera harrisonii |
Boechera glareosa |
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Phenology | Flowering May–Jun. | Flowering May–Jun. |
Habitat | Limestone and quartzite cliffs | Conglomerate and limestone outcrops in pinyon-juniper and mountain shrub-conifer communities |
Elevation | 1500-1600 m (4900-5200 ft) | 2000-2600 m (6600-8500 ft) |
Distribution |
UT |
CO; UT |
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.) |
Specimens of Boechera glareosa originally were identified as Arabis microphylla var. macounii (= B. macounii) by R. C. Rollins. The former (a sexual species) is distinguished from the latter (an apomictic hybrid) by having wider (1–2 versus 0.5–0.8 mm) petals, fewer (2–9 versus mostly 9–16) cauline leaves, and fewer (7–15 versus 10–33) flowers per inflorescence. Boechera glareosa is known only from Moffat County, Colorado, and Summit and Uintah counties, Utah. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 383. | FNA vol. 7, p. 380. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Arabis harrisonii, B. microphylla var. harrisonii | |
Name authority | (S. L. Welsh) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 266. (2007) | Dorn: Brittonia 55: 1, fig. 1. (2003) |
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