Boechera dentata |
Boechera dispar |
|
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Short's rockcress |
pinyon rock cress |
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Habit | Biennials; short-lived; sexual; caudex present or absent. | Perennials; usually long-lived; sexual; caudex often woody. |
Stems | usually 2–4 per plant or caudex branch, arising from margin of rosette near ground surface, or arising laterally proximal to sterile shoots, 2–6 dm, pubescent proximally, trichomes short-stalked, 2–4-rayed, 0.15–0.4 mm, sparsely pubescent or glabrous distally. |
usually 1 per caudex branch, arising from center of rosette near ground surface, 0.9–3 dm, densely pubescent proximally, trichomes short-stalked, 5–12-rayed, 0.1–0.3 mm, sparsely pubescent to glabrescent distally. |
Basal leaves | blade obovate to oblanceolate, (6–)10–45 mm wide, margins dentate, not ciliate, surfaces sparsely pubescent, abaxially trichomes short-stalked, 3- or 4-rayed, 0.15–0.4 mm, adaxially simple ones, 0.4–1 mm. |
blade linear-oblanceolate, 2–5 mm wide, margins entire, not ciliate, surfaces densely pubescent, trichomes short-stalked, 5–12(–16)-rayed, 0.1–0.3 mm. |
Cauline leaves | 4–20, rarely concealing stem; blade auricles 1–8 mm, surfaces of distalmost leaves sparsely pubescent. |
1–5, not concealing stem; blade without auricles, surfaces of distalmost leaves pubescent. |
Racemes | 14–66-flowered, sparingly branched. |
4–15(–20)-flowered, unbranched. |
Flowers | divaricate at anthesis; sepals glabrous or sparsely pubescent; petals white or cream, 2–3.5 × 0.7–1 mm, glabrous; pollen ellipsoid. |
ascending at anthesis; sepals pubescent; petals purple to lavender, 3.5–6 × 1–1.5 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | divaricate-ascending to slightly descending, straight, 1–6 mm, glabrous or pubescent, trichomes appressed, branched. |
ascending, straight, 4–15(–25) mm, pubescent, trichomes appressed, branched. |
Fruits | divaricate-ascending to slightly descending, not appressed to rachis, not secund, straight or slightly curved, edges parallel, 1.3–4.2 cm × 0.7–0.8 mm; valves usually sparsely pubescent throughout, rarely glabrous; ovules 14–44 per ovary; style 0.1–0.5 mm. |
divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 4–7.3 cm × 2.7–4 mm; valves glabrous; ovules 44–52 per ovary; style 0.05–0.1 mm. |
Seeds | uniseriate, 0.7–1.1 × 0.5–0.6 mm; not winged. |
uniseriate, 1.9–2.3 mm in diam.; wing continuous, 0.3–0.5 mm wide. |
Boechera dentata |
Boechera dispar |
|
Phenology | Flowering Apr–Jun. | Flowering Apr–May. |
Habitat | Bluffs and rocky ledges, wooded slopes, floodplains | Rocky slopes and gravelly soil in desert scrub and pinyon-juniper communities |
Elevation | 100-300 m (300-1000 ft) | 1500-2300 m (4900-7500 ft) |
Distribution |
AL; AR; DC; IA; IL; IN; KS; KY; MD; MI; MN; MO; NE; NY; OH; OK; PA; SD; TN; VA; WI; WV; ON
|
CA; NV |
Discussion | Sisymbrium dentatum Torrey is an illegitimate name that pertains to Iodanthus dentatus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera dispar is a distinctive sexual diploid that is known from Inyo, Mono, and San Bernardino counties, California, and Nye County, Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 373. | FNA vol. 7, p. 374. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Shortia dentata, Arabis dentata var. phalacrocarpa, Arabis perstellata var. shortii, Arabis shortii, Arabis shortii var. phalacrocarpa, B. shortii, Iodanthus dentatus | Arabis dispar, Arabis juniperina, Arabis nardina, Arabis salubris |
Name authority | (Rafinesque) Al-Shehbaz & Zarucchi: Harvard Pap. Bot. 13: 293. (2008) | (M. E. Jones) Al-Shehbaz: Novon 13: 384. (2003) |
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