Draba alpina
Draba cinerea
alpine Draba
gray-leaf Draba, gray-leaf whitlow-grass
unbranched, (0.3–)0.5–1.7(–2.8) dm, pubescent throughout, trichomes simple and 2-rayed, 0.3–0.8 mm, with 3–5-rayed ones, 0.1–0.3 mm.
unbranched, (0.3–)0.5–1.6(–2.7) dm, pubescent throughout, trichomes 4–10-rayed, 0.1–0.3 mm, (often some rays branched, simple trichomes sparse, to 0.6 mm).
rosulate; petiolate;
petiole base (not thickened), ciliate, (trichomes simple, 0.3–1 mm);
blade oblanceolate to obovate or lanceolate to oblong, 0.8–3(–4.5) cm × 2.5–6(–9) mm, margins entire, surfaces abaxially pubescent with stalked, 2–4-rayed trichomes, 0.1–0.5 mm, with simple ones (midvein obscure, not thickened), adaxially glabrous or sparsely pubescent with simple and stalked, 2–4-rayed trichomes.
rosulate; petiolate;
petiole base and proximalmost margin ciliate, (trichomes simple, 0.2–0.8 mm);
blade oblanceolate to narrowly obovate or linear-lanceolate, 0.4–1.5 cm × 1–5 mm, margins usually entire, rarely with 1 tooth on each side, surfaces densely pubescent with minutely stalked, stellate, 8–12-rayed, trichomes 0.1–0.25 mm, (midvein obscure abaxially, apex trichomes simple).
0.
0–3(–5);
sessile;
blade ovate or oblong to lanceolate, margins entire, surfaces pubescent as basal.
6–18-flowered, ebracteate, considerably elongated in fruit;
rachis not flexuous, pubescent as stem.
(3–)5–17(–24)-flowered, ebracteate, elongated in fruit;
rachis not flexuous, pubescent as stem.
sepals (purplish tinged), narrowly ovate, 2.5–3 mm, pubescent, (trichomes simple and fewer, stalked, 2-rayed);
petals bright yellow, narrowly obovate, 3.5–5 × 1.7–2.5 mm;
anthers ovate, 0.3–0.4 mm.
sepals ovate, 1.7–2.5 mm, pubescent, (trichomes simple and short-stalked, 2- or 3-rayed);
petals white, spatulate to obovate, 3.5–4.5 × 1.5–2 mm;
anthers ovate, 0.3–0.4 mm.
ascending to divaricate-ascending, straight or, sometimes, slightly curved upwards, 4–14(–30) mm, pubescent, trichomes simple and 2–4-rayed.
divaricate-ascending or ascending, straight, (3–)4–7(–9) mm, pubescent as stem.
elliptic, plane, flattened, 6–10 × 2–3 mm;
valves glabrous or glabrescent, trichomes simple, (not confined to replum);
ovules 12–24 per ovary;
style 0.2–0.3 mm (stigma about as wide as style).
oblong to elliptic, plane, slightly flattened, 5–8 × 2–3 mm;
valves pubescent, trichomes short-stalked, 2–5-rayed, 0.05–0.3 mm, (some rays branched);
ovules 20–36(–42) per ovary;
style (0.1–)0.2–1 mm.
(pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm.
ovoid, 0.6–0.8 × 0.4–0.6 mm.
= 80.
= 48.
Draba alpina
Draba cinerea
The synonymy above includes two North American names overlooked by C. L. Hitchcock (1941) and R. C. Rollins (1993). Draba alpina was broadly delimited by O. E. Schulz (1927) and included 17 varieties, some of which (e.g., corymbosa, oxycarpa, pilosa) are recognized herein as distinct species. The name D. alpina was so misapplied that it was used for any circumpolar or alpine, scapose, yellow-flowered, perennial Draba. Various chromosome numbers (e.g., 2n = 64, 80, 112, 120; S. I. Warwick and I. A. Al-Shehbaz 2006) have been reported for the species. As circumscribed here, it has the narrow distribution outlined above and includes plants with 2n = 80. Reports of the species from Alaska, Canadian Northwest Territories and Yukon, Siberia, eastern Asia, Russian Far East, and the Central Asian republics are either suspect or very unlikely. The entire D. alpina complex (including the above three species, D. glacialis Adams, D. macounii, etc.) is in need of critical molecular, cytological, and morphological study.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Draba cinerea is a polymorphic species in which tetraploid, hexaploid, heptaploid, and octoploid chromosome counts (all based on x = 8) have been reported (e.g., R. C. Rollins 1993). Although we have not seen the type collection, we tentatively consider the taxon to be hexaploid, which is the predominant ploidy level throughout the species range, including North America, and also from its type region in Siberia.
Hexaploid Draba cinerea is closely related to decaploid (2n = 80) D. arctica, from which it is distinguished with difficulty. In general, D. cinerea has 1–3(–5)-leaved stems, basal leaf blades usually not terminated with simple trichomes and with obscure midveins abaxially, petals 3.5–4.5 mm, and seeds 0.6–0.8 × 0.4–0.6 mm. By contrast, D. arctica has leafless or 1(–3)-leaved stems, basal leaf blades terminated with simple or 2-rayed trichomes and with midveins distinct abaxially, petals 3.5–6 mm, and seeds (0.8–)0.9–1.1 × (0.6–)0.7–0.8 mm.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
WildflowerSearch
iNaturalist
USDA Plants Database
BC
PNW Herbaria
