Draba praealta |
Draba maguirei |
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Draba, tall Draba, tall whitlow-grass, tall whitlow-grass Draba |
Maguire's Draba |
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Habit | Annuals or perennials; (short-lived); caudex simple or branched; not scapose. | Perennials; (cespitose, forming loose mats); caudex branched (with some persistent leaf bases, branches often creeping, sometimes terminating in sterile rosettes); scapose. |
Stems | branched or unbranched, (0.5–)0.8–3.2(–3.8) dm, pubescent throughout, trichomes 3–5-rayed, 0.1–0.4 mm, with simple and 2-rayed ones, 0.4–1 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; subsessile; petiole base ciliate, (trichomes simple and 2-rayed, 0.2–0.8 mm); blade oblanceolate, (0.7–)1–3.5(–4.5) cm × 1.5–7(–9) mm, margins usually dentate, rarely entire, surfaces pubescent, abaxially with stalked, 3–6-rayed trichomes, 0.1–0.5 mm, adaxially with stalked, 3–5-rayed, 0.1–0.6 mm, and simple ones, to 0.8 mm. |
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 or) 2–5(–9); sessile; blade ovate to lanceolate, margins dentate or entire, surfaces pubescent as basal. |
0. |
Racemes | (5–)8–30(–37)-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem. |
5–18(–23)-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous. |
Flowers | (late-season ones petaliferous); sepals ovate, 1.7–2.5 mm, pubescent, (trichomes simple and stalked, 2-rayed); petals white, oblanceolate to spatulate, 2.8–3.5(–4) × 0.8–1.2 mm; anthers ovate, 0.2–0.3 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 to ascending or suberect (not appressed to rachis), straight, (3–)4–10(–12) mm, pubescent, trichomes 3–5-rayed (0.1–0.4 mm), and sometimes simple. |
divaricate-ascending to ascending (not expanded basally), straight, 5–13(–18) mm, glabrous. |
Fruits | (erect, not appressed to rachis) lanceolate to linear-lanceolate, plane, flattened, (5–)7–12(–15) × 1.5–2.5(–3) mm; valves puberulent, trichomes simple and short-stalked, 2–4-rayed, 0.05–0.25 mm; ovules (24–)30–52 per ovary; style 0.03–0.1(0.15) 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 | oblong, 0.8–1.1 × 0.5–0.6 mm, (often apiculate). |
ovoid to oblong, 1.6–2 × 1–1.3 mm. |
2n | = 56. |
= 16, 32. |
Draba praealta |
Draba maguirei |
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Phenology | Flowering Jun–Aug. | Flowering May–Jul. |
Habitat | Rocky pine slopes, subalpine areas, alpine meadows, grassy volcanic ridges, woodlands, damp rocky areas, limestone talus, shale cliffs, steep hillsides | Dolomite outcrops, talus, rocky slopes |
Elevation | 1200-2900 m (3900-9500 ft) | 1600-2900 m (5200-9500 ft) |
Distribution |
CA; ID; MT; NV; OR; WA; WY; AB; BC; NT; YT; e Asia (Russian Far East [Chukchi Peninsula])
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UT |
Discussion | Morphological and chromosomal evidence (M. D. Windham, unpubl.) suggests that Draba praealta may be an allopolyploid originating through hybridization between D. albertina and D. cana. Both R. C. Rollins (1993) and N. H. Holmgren (2005b) placed D. lonchocarpa var. dasycarpa in the synonymy of D. lonchocarpa. G. A. Mulligan (1974) indicated that the type of var. dasycarpa does not belong to that species and he correctly annotated its isotype (Macoun 64454, CAN) as D. praealta. Mulligan (1976) and Rollins indicated that D. praealta occurs in Alaska, but we have not seen unequivocal material from the state. We have not seen the material on which A. E. Katenin and V. V. Petrovsky (1995) based their record from the Russian Far East. (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. 331. | FNA vol. 7, p. 318. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. cascadensis, D. columbiana, D. dolichopoda, D. lapilutea, D. lonchocarpa var. dasycarpa, D. praealta var. yellowstonensis, D. yellowstonensis | |
Name authority | Greene: Pittonia 3: 306. (1898) | C. L. Hitchcock: Revis. Drabas W. N. Amer., 70, plate 5, figs. 37a–c. (1941) |
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