Draba daviesiae |
Draba arida |
|
---|---|---|
bitter root Draba |
desert Draba |
|
Habit | Perennials; (densely pulvinate); caudex branched (branches elongated, loose, with persistent leaf remains, terminating in flowering or sterile shoots); scapose. | Perennials; (cespitose); caudex branched (with persistent leaf remains, branches relatively short); not scapose. |
Stems | unbranched, (0.05–)0.2–0.6 dm, glabrous. |
usually unbranched, (0.3–)0.4–1 dm, pubescent throughout, trichomes simple and 2-rayed, 0.4–1.4 mm, and shorter, 2–4-rayed ones, 0.05–0.3 mm. |
Basal leaves | (densely imbricate); rosulate; petiolate; petiole ciliate throughout; blade (fleshy), oblong to obovate or oblanceolate, 0.3–0.7(–1) cm × 1–2(–2.5) mm, margins entire, (ciliate, trichomes simple, 0.1–0.5 mm, apex obtuse), surfaces glabrous (midvein obscure abaxially). |
rosulate; subsessile; petiole not ciliate; blade obovate to spatulate or oblanceolate, 0.6–1.9(–2.4) cm × 2–5(–8) mm, (base ciliate, trichomes simple and 2-rayed), margins entire, surfaces abaxially pubescent with stalked, (2–)4-rayed trichomes, 0.3–0.6 mm, adaxially with simple and stalked, 2-rayed trichomes, 0.3–0.6 mm, and smaller, 3- or 4-rayed ones. |
Cauline leaves | 0. |
(1 or) 2–5; sessile; blade oblong to oblanceolate or ovate, margins entire, surfaces pubescent as basal. |
Racemes | 2–8(–10)-flowered, ebracteate, (subcorymbose), slightly elongated in fruit; rachis not flexuous, glabrous. |
12–40-flowered, ebracteate, slightly elongated in fruit; rachis not flexuous, pubescent, trichomes simple and 2–4-rayed. |
Flowers | sepals oblong, 1.5–2.2 mm, glabrous; petals pale to bright yellow, spatulate, 3.5–4 × 1–2 mm; anthers ovate, 0.3–0.4 mm. |
sepals broadly ovate, 2–2.7 mm, pubescent, (trichomes simple and short-stalked, 2–4-rayed); petals yellow, spatulate to oblanceolate, 3.5–5 × 1.4–2 mm; anthers oblong, 0.4–0.6 mm. |
Fruiting pedicels | divaricate-ascending (not decurrent basally), straight, 4–10 mm, glabrous. |
horizontal to divaricate-ascending, straight, (3–)4–8 mm, pubescent, trichomes simple and 2–4-rayed (0.1–0.5 mm). |
Fruits | ovate to oblong-elliptic, plane, flattened, 4–8 × 2–4 mm; valves (obscurely veined), glabrous; ovules 6–14 per ovary; style 0.1–0.5 mm. |
elliptic or ovate to lanceolate, plane, slightly inflated basally, 4–7 × 2.5–3.5 mm; valves pubescent, trichomes simple and stalked, 2–4-rayed, 0.05–0.4 mm; ovules 8–12 per ovary; style 0.5–1.2(–1.4) mm. |
Seeds | ovoid, 1.2–1.5 × 0.8–1 mm. |
ovoid, 1–1.4 × 0.6–0.8 mm. |
2n | = 24. |
|
Draba daviesiae |
Draba arida |
|
Phenology | Flowering Jul–Aug. | Flowering May–Jul. |
Habitat | Talus slopes, rock crevices and cracks, rocky ridges and slides, alpine meadows | Rock crevices and gravelly soil in conifer and subalpine shrub communities |
Elevation | 2700-2900 m (8900-9500 ft) | 2100-3400 m (6900-11200 ft) |
Distribution |
MT |
NV |
Discussion | Although originally described as a variety of Draba apiculata (= D. globosa), D. daviesiae is distinct morphologically. It is easily distinguished from the former by its densely pulvinate habit, obtuse leaf blades, and obscurely veined fruit valves. By contrast, D. globosa exhibits a cespitose but non-pulvinate habit, acute leaf blades, and prominently veined fruit valves. Draba daviesiae is known from the Bitterroot Mountains in Ravalli County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba arida is a sexually reproducing, diploid member of the D. ventosa complex that may have been involved in the origin of the more widespread apomictic triploids (M. A. Beilstein and M. D. Windham 2003). The species is known from the Monitor, Toiyabe, and Toquima ranges in Lander and Nye counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 305. | FNA vol. 7, p. 292. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. apiculata var. daviesiae, D. densifolia var. daviesiae | |
Name authority | (C. L. Hitchcock) Rollins: Contr. Gray Herb. 214: 5. (1984) | C. L. Hitchcock: Revis. Drabas W. N. Amer., 52, plate 3, fig. 23. (1941) |
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