Draba nemorosa
Sp. Pl. 2: 643. 1753.
Annuals; not scapose. Stems unbranched or branched proximally, (0.3–)0.6–4.5(–6) dm, densely pubescent proximally, glabrous distally, trichomes simple, 0.5–1.3 mm, and stalked, 2–4-rayed, 0.1–0.5 mm. Basal leaves rosulate or not, petiolate; petiole ciliate throughout; blade oblong-obovate or oblanceolate, (0.4–)1–3.5(–5) cm × (2–)5–15(–20) mm, margins usually dentate to denticulate, rarely subentire, surfaces sparsely to densely pubescent with stalked, 2- or 3-rayed, and cruciform trichomes, 0.1–0.5 mm. Cauline leaves 4–12(–15); sessile; blade broadly ovate to oblong, margins dentate or denticulate, surfaces pubescent, abaxially as basal, adaxially with primarily simple, and 2- or 3-rayed trichomes. Racemes (10–)18–60(–92)-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous (straight), glabrous. Fruiting pedicels divaricate, straight, 7–28(–35) mm [(1.5–)2–7 times longer than fruit], glabrous. Flowers: sepals ovate, (0.7–)0.9–1.6 mm, sparsely pubescent, (trichomes simple); petals yellow, spatulate to oblanceolate, (1.2–)1.7–2.2(–2.5) × (0.4–)0.6–1 mm, (deeply notched); anthers broadly ovate to subreniform, 0.1–0.2 mm. Fruits oblong to elliptic or, rarely, oblong-oblanceolate, plane, slightly flattened, (3–)5–8 (–10) × 1.5–2.5 mm; valves glabrous or puberulent, trichomes simple, antrorse, 0.05–0.2 mm; ovules (30–)36–60(–72) per ovary; style 0.01–0.1 mm. Seeds ovoid, 0.5–0.7(–0.8) × 0.3–0.4(–0.5) mm. 2n = 16.
Phenology: Flowering Apr–Jul.
Habitat: Rock outcrops, open wooded slopes, meadows and prairies, stream banks, roadsides, disturbed gravelly grounds, waste places
Elevation: 0-2700 m
Distribution
Alta., B.C., Man., N.W.T., Nunavut, Ont., Que., Sask., Yukon, Alaska, Calif., Colo., Idaho, Iowa, Mich., Minn., Mont., Nebr., Nev., N.Dak., Oreg., S.Dak., Utah, Wash., Wis., Wyo., Europe, Asia, introduced also in Australia.
Discussion
Selected References
None.