Draba standleyi |
Draba graminea |
|
---|---|---|
Standley's Draba |
Rocky Mountain Draba |
|
Habit | Perennials; (densely pulvinate); caudex branched (with persistent, thickened petioles, branches compact); not scapose. | Perennials; (cespitose); caudex simple or branched (with persistent leaf bases); not scapose. |
Stems | unbranched, 0.3–1.3(–1.7) dm, usually glabrous throughout or sparsely pubescent proximally, rarely sparsely pubescent distally, trichomes simple and 2-rayed, 0.1–0.7 mm. |
unbranched, 0.1–0.5(–0.8) dm, usually pubescent throughout, rarely glabrous, trichomes simple or subsessile, 2-rayed or spurred, (crisped), 0.1–0.5 mm. |
Basal leaves | (not imbricate); rosulate; petiolate; petiole ciliate, (trichomes usually simple, rarely 2-rayed, not setiform); blade narrowly oblanceolate to linear-lanceolate, (strongly differentiated into blade and petiole), (1.2–)1.8–6(–8.5) cm × 1–5(–7) mm, margins entire or sparsely denticulate, (ciliate as petiole; midvein not prominent), surfaces glabrous or pubescent, usually with simple trichomes 0.1–0.8 mm, rarely 2-rayed. |
rosulate; petiolate; petiole ciliate, (trichomes usually straight and simple, rarely also 2-rayed, 0.2–0.6(–0.8) mm); blade linear to linear-oblanceolate, (0.5–)1–4 cm × 0.3–2(–3) mm, margins entire (pubescent as petiole), surfaces glabrous. |
Cauline leaves | 1–8; sessile; blade lanceolate to narrowly oblong, margins usually entire, surfaces pubescent as basal. |
(1–)3–9(–12) (as bracts); sessile; blade linear to oblanceolate or lanceolate, margins entire, (ciliate proximally, similar to basal). |
Racemes | 5–17(–23)-flowered, ebracteate, elongated in fruit; rachis not flexuous, usually glabrous, rarely pubescent, trichomes simple and 2-rayed, (non-crisped). |
3–15-flowered, bracteate, elongated in fruit; rachis not flexuous, usually pubescent as stem, rarely glabrous. |
Flowers | sepals ovate, 2–2.5 mm, pubescent, (trichomes simple); petals yellow, oblanceolate, 4–6 × 1.5–2 mm; anthers oblong, 0.6–0.8 mm. |
sepals ovate, 1.5–2.5 mm, glabrous or pubescent, (trichomes simple and short-stalked, 2-rayed); petals yellow, spatulate to obovate, 3–5 × 1.5–3 mm; anthers ovate, 0.3–0.5 mm. |
Fruiting pedicels | divaricate-ascending or ascending, straight, 3–9(–13) mm, usually glabrous, rarely sparsely pubescent, trichomes simple. |
divaricate-ascending, usually straight, rarely curved upward, 3–10(–15) mm, usually pubescent as stem, rarely glabrous. |
Fruits | linear-elliptic to elliptic, twisted or plane, flattened, 5–10(–13) × 1.5–2.5 mm; valves usually glabrous, rarely puberulent, trichomes simple, 0.05–0.1 mm; ovules 12–24 per ovary; style 0.7–1.4(–1.8) mm. |
ovate-elliptic to lanceolate, slightly twisted or plane, flattened, 5–11 × 2.5–5 mm; valves glabrous; ovules 8–16 per ovary; style 0.2–0.7 mm. |
Seeds | ovoid, 1–1.2 × 0.7–0.8 mm. |
ovoid, 1.2–1.5 × 0.7–1 mm. |
2n | = 18. |
|
Draba standleyi |
Draba graminea |
|
Phenology | Flowering Jun–Aug. | Flowering Jul–Sep. |
Habitat | Igneous rock outcrops, stabilized talus slopes | Rocky areas and ridges, alpine tundra, gravel bars in streams |
Elevation | 1800-3100 m (5900-10200 ft) | 3000-4100 m (9800-13500 ft) |
Distribution |
AZ; NM; TX |
CO
|
Discussion | Of conservation concern. Draba standleyi is a distinctive species that is sporadically distributed in the mountains of southwestern United States. It is known from the Chiricahua Mountains (Cochise County, southeastern Arizona), the Organ Mountains and Black Range (Dona Ana and Sierra counties, south-central New Mexico), and the Davis Mountains (Jeff Davis County, western Texas). It has not been reported from Mexico, though it is very likely to occur there. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba graminea is occasionally confused with D. crassa, which occupies similar habitats and elevations. It is easily distinguished from the latter by having narrower [0.3–2(–3) versus 2.5–8(–10) mm wide] basal leaves and bracteate (versus ebracteate) racemes. It is known to us only from Hinsdale, La Plata, Ouray, San Juan, and San Miguel counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 340. | FNA vol. 7, p. 309. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. gilgiana, D. chrysantha var. gilgiana | Braya graminea, D. chrysantha var. graminea, D. chrysantha var. hirticaulis |
Name authority | J. F. Macbride & Payson: Ann. Missouri Bot. Gard. 5: 150. (1918) | Greene: Pl. Baker. 3: 5. (1901) |
Web links |