Draba trichocarpa |
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stanley creek Draba |
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Habit | Perennials; (cespitose, densely pulvinate); caudex branched (covered with persistent leaves, branches sometimes terminating in sterile rosettes); scapose. |
Stems | unbranched, 0.07–0.35 dm, pubescent throughout, trichomes (soft), stalked, subdendritic, (somewhat crisped), 0.1–0.5 mm, (simple ones absent). |
Basal leaves | (densely imbricate); rosulate; sessile; blade oblong to obovate, 0.2–0.4 cm × 0.5–1.5 mm, margins entire, (ciliate, trichomes simple and branched, subdendritic, or spurred, 0.3–0.8 mm), surfaces sparsely pubescent, abaxially with stalked, 4–6-rayed stellate trichomes, 0.1–0.4 mm, adaxially with simple and 4–6-rayed trichomes, mainly on distal 1/2. |
Cauline leaves | 0 (or 1); sessile; blade similar to basal. |
Racemes | 2–9-flowered, ebracteate, slightly elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals ovate, 2–3 mm, pubescent, (trichomes short-stalked); petal color unknown, broadly obovate, 2–4 × 2–2.5 mm; anthers oblong, 0.5–0.6 mm. |
Fruiting pedicels | divaricate-ascending to ascending, straight, 1–4.5 mm, pubescent as stem. |
Fruits | ovoid, plane, slightly inflated basally, flattened distally, 2–6 × 2–3.5 mm; valves densely pubescent, trichomes 4-rayed, 0.1–0.4 mm, (often some rays spurred or branched); ovules 4–10 per ovary; style 0.3–0.7 mm. |
Seeds | oblong, 1.4–2 × 0.8–1.2 mm. |
Draba trichocarpa |
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Phenology | Flowering Jun–Jul. |
Habitat | Gravelly metamorphic soil at ecotone between sagebrush steppe and open conifer forests |
Elevation | ca. 2000 m (ca. 6600 ft) |
Distribution |
ID |
Discussion | Of conservation concern. Draba trichocarpa is an apomictic polyploid that appears to be closely related to D. novolympica. It is readily distinguished from that species by the primarily dendritic trichomes (and absence of simple trichomes) on the stems, pedicels, and fruits. Draba trichocarpa is known from the Stanley Basin of central Idaho (Custer County). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 344. |
Parent taxa | |
Sibling taxa | |
Name authority | Rollins: Contr. Gray Herb. 214: 4. (1984) |
Web links |