Boechera dentata |
Boechera constancei |
|
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Short's rockcress |
Constance's Rock cress |
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Habit | Biennials; short-lived; sexual; caudex present or absent. | Perennials; long-lived; sexual; caudex 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, elevated above ground surface on woody base, 1.2–3 dm, glabrous throughout. |
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 narrowly oblanceolate, 1.5–4 mm wide, margins entire, ciliate, trichomes (simple, mixed with fewer stalked, 2-rayed), 0.3–0.8 mm, surfaces glabrous. |
Cauline leaves | 4–20, rarely concealing stem; blade auricles 1–8 mm, surfaces of distalmost leaves sparsely pubescent. |
6–12, not concealing stem; blade auricles absent, surfaces of distalmost leaves glabrous. |
Racemes | 14–66-flowered, sparingly branched. |
5–15-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. |
divaricate-ascending at anthesis; sepals glabrous; petals creamy white, 6–8 × 1.5–2 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | divaricate-ascending to slightly descending, straight, 1–6 mm, glabrous or pubescent, trichomes appressed, branched. |
arched, strongly recurved proximally, 4–12 mm, glabrous. |
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. |
pendent, not appressed to rachis, usually secund, straight or slightly curved, edges often somewhat undulate (not parallel), 4–7.5 cm × 3–3.5 mm; valves glabrous; ovules 18–28 per ovary; style 2.5–5 mm. |
Seeds | uniseriate, 0.7–1.1 × 0.5–0.6 mm; not winged. |
uniseriate, 3–4 × 2.5–3 mm; wing continuous, 0.5–1 mm wide. |
2n | = 14. |
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Boechera dentata |
Boechera constancei |
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Phenology | Flowering Apr–Jun. | Flowering May. |
Habitat | Bluffs and rocky ledges, wooded slopes, floodplains | Steep ridges, serpentine slopes |
Elevation | 100-300 m (300-1000 ft) | 1200-1900 m (3900-6200 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
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CA |
Discussion | Sisymbrium dentatum Torrey is an illegitimate name that pertains to Iodanthus dentatus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera constancei was originally treated as a variety of Arabis (Boechera) suffrutescens; it is easily separated from that species by its non-auriculate cauline leaf blades, longer (6–8 versus 4.5–6 mm) petals that are creamy white (versus purple or rose-tipped), much longer style (2.5–5 versus 0.4–1.2 mm), and exerted anthers. This distinctive sexual diploid is thus far known only from the west slope of the Sierra Nevada in Plumas County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 373. | FNA vol. 7, p. 371. |
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 constancei, Arabis suffrutescens var. perstylosa |
Name authority | (Rafinesque) Al-Shehbaz & Zarucchi: Harvard Pap. Bot. 13: 293. (2008) | (Rollins) Al-Shehbaz: Novon 13: 384. (2003) |
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