Draba graminea |
Draba maguirei |
|
---|---|---|
Rocky Mountain Draba |
Maguire's Draba |
|
Habit | Perennials; (cespitose); caudex simple or branched (with persistent leaf bases); not scapose. | Perennials; (cespitose, forming loose mats); caudex branched (with some persistent leaf bases, branches often creeping, sometimes terminating in sterile rosettes); scapose. |
Stems | 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. |
unbranched, (0.4–)0.7–1.7(–2.2) dm, usually glabrous, rarely proximalmost parts and sterile shoots pubescent, trichomes short-stalked, 2–4-rayed, 0.2–0.5 mm. |
Basal leaves | 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. |
rosulate; sessile; blade oblanceolate, (0.5–)0.7–1.4(–2) cm × 1.5–3.5(–5) mm, margins entire, surfaces pubescent with stalked, cruciform, and 2- or 3-rayed trichomes, 0.2–0.6 mm, (sometimes trichomes only on margins or apex, not ciliate, midvein obscure abaxially). |
Cauline leaves | (1–)3–9(–12) (as bracts); sessile; blade linear to oblanceolate or lanceolate, margins entire, (ciliate proximally, similar to basal). |
0. |
Racemes | 3–15-flowered, bracteate, elongated in fruit; rachis not flexuous, usually pubescent as stem, rarely glabrous. |
5–18(–23)-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous. |
Flowers | 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. |
sepals ovate, 2.5–4 mm, glabrous; petals yellow, oblanceolate, 5–7 × 2–3 mm; anthers ovate, 0.5–0.6 mm. |
Fruiting pedicels | divaricate-ascending, usually straight, rarely curved upward, 3–10(–15) mm, usually pubescent as stem, rarely glabrous. |
divaricate-ascending to ascending (not expanded basally), straight, 5–13(–18) mm, glabrous. |
Fruits | 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. |
broadly ovate to lanceolate, plane (not curved), flattened, (3–)4–6.5(–8) × 2–3 mm; valves glabrous or puberulent, trichomes simple, 0.05–0.2 mm; ovules 4–8 per ovary; style 0.6–1.7 mm. |
Seeds | ovoid, 1.2–1.5 × 0.7–1 mm. |
ovoid to oblong, 1.6–2 × 1–1.3 mm. |
2n | = 18. |
= 16, 32. |
Draba graminea |
Draba maguirei |
|
Phenology | Flowering Jul–Sep. | Flowering May–Jul. |
Habitat | Rocky areas and ridges, alpine tundra, gravel bars in streams | Dolomite outcrops, talus, rocky slopes |
Elevation | 3000-4100 m (9800-13500 ft) | 1600-2900 m (5200-9500 ft) |
Distribution |
CO
|
UT |
Discussion | 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.) |
Draba maguirei is known from the Bear River Range in Cache County. Despite this very narrow distribution, the species includes two ploidy levels (diploid and tetraploid) that are morphologically and ecologically distinct (M. D. Windham, unpubl.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 309. | FNA vol. 7, p. 318. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | Braya graminea, D. chrysantha var. graminea, D. chrysantha var. hirticaulis | |
Name authority | Greene: Pl. Baker. 3: 5. (1901) | C. L. Hitchcock: Revis. Drabas W. N. Amer., 70, plate 5, figs. 37a–c. (1941) |
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