Draba brachystylis |
Draba kassii |
|
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shortstyle Draba |
kass' Draba |
|
Habit | Annuals or perennials; (short-lived); caudex often simple (poorly developed); not scapose. | Perennials; caudex branched (densely covered with persistent petiole remains, branches sometimes terminating in sterile rosettes); scapose. |
Stems | unbranched or branched, 0.6–3(–3.7) dm, pubescent throughout, trichomes simple, 0.4–0.9 mm, and 2–4-rayed, 0.05–0.4 mm. |
unbranched, 0.5–1.8 dm, glabrous. |
Basal leaves | rosulate; subsessile; petiole base ciliate, (trichomes simple, 0.3–0.9 mm); blade oblanceolate, 1–3.5 cm × 4–7(–12) mm, margins entire or denticulate, surfaces pubescent, abaxially with stalked, (2–)4-rayed trichomes, 0.1–0.5 mm, adaxially with simple trichomes, 0.2–0.6 mm, with smaller, 2–4-rayed ones. |
rosulate; long-petiolate; petiole ciliate throughout; blade oblanceolate to linear-oblanceolate, 1.5–5.5 cm × (1.5–)2–5.5 mm, margins entire (ciliate, trichomes simple, 0.2–1 mm), surfaces abaxially sparsely pubescent with short-stalked, submalpighiaceous trichomes, 0.3–1.3 mm, sometimes with 3- or 4-rayed ones, adaxially usually glabrous, rarely sparsely pubescent. |
Cauline leaves | (1 or) 2–6(–8); sessile; blade lanceolate or oblanceolate to ovate, margins entire or denticulate, surfaces pubescent as basal. |
0. |
Racemes | (5–)10–35(–47)-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem. |
3–8(–10)-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, glabrous. |
Flowers | sepals ovate, 2–2.7 mm, pubescent, (trichomes simple and short-stalked, 2-rayed); petals pale yellow (fading white), oblanceolate, 2.5–3.7 × 0.9–1.2 mm; anthers ovate, 0.2–0.3 mm. |
sepals broadly ovate, 2–3 mm, subapically sparsely pubescent, (trichomes simple); petals yellow, oblanceolate, 4.5–7 × 1.2–2 mm; anthers ovate, 0.4–0.5 mm. |
Fruiting pedicels | divaricate-ascending, straight or only slightly curved upward, (1.5–)3–8(–10) mm, pubescent throughout, trichomes simple and stalked, 2–4-rayed. |
ascending to divaricate-ascending, straight, 5–14(–17) mm, glabrous. |
Fruits | narrowly elliptic to lanceolate, plane, flattened, (7–)10–16(–19) × 2–3.5 mm; valves pubescent, trichomes simple, spurred, and short-stalked, 2-rayed, 0.05–0.2(–0.3) mm; ovules 20–36(–42) per ovary; style 0.2–0.6(–0.8) mm. |
elliptic to oblong-elliptic, plane, flattened, 3–10(–14) × 2–3 mm; valves glabrous; ovules 20–28 per ovary; style 0.6–1 mm. |
Seeds | oblong, 0.9–1.3 × 0.6–0.7 mm. |
oblong, 1.2–1.4 × 0.7–0.8 mm. |
2n | = 44. |
= 22. |
Draba brachystylis |
Draba kassii |
|
Phenology | Flowering Jun–Jul. | Flowering Apr–Jun. |
Habitat | Fir and aspen communities, moist areas on rocky slopes | Quartzite and granitic outcrops |
Elevation | 1700-3000 m (5600-9800 ft) | 2100-2600 m (6900-8500 ft) |
Distribution |
UT |
UT |
Discussion | Of conservation concern. Based on morphological and chromosomal data (L. Allphin and M. D. Windham, unpubl.), Draba brachystylis is hypothesized to be an allopolyploid derived through hybridization between D. albertina and D. santaquinensis. It is known to us only from Cache, Duchesne, Juab, Salt Lake, and Utah counties. C. L. Hitchcock (1941) indicated that the species grows in the Charleston Mountains of Clark County, Nevada, but we have not seen unequivocal material of it from that area. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba kassii is a distinctive species that is known from the Deep Creek Mountains in Juab and Tooele counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 297. | FNA vol. 7, p. 315. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Rydberg: Bull. Torrey Bot. Club 29: 240. (1902) | S. L. Welsh: Great Basin Naturalist 46: 264. (1986) |
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