Draba adamsii Ledebour

Perennials; caudex branched (with persistent, thickened leaf midveins); scapose. Stems unbranched, (0.05-)0.1-0.8 dm, pubescent throughout, sometimes sparsely so distally, trichomes simple, 0.3-0.7 mm, and 2-4-rayed, 0.05-0.2 mm. Basal leaves (not imbricate); rosulate; petiolate; petiole ciliate, (trichomes simple and 2-rayed, 0.4-1.3 mm); blade oblanceolate, 0.5-1.1 cm × 1.5-4 mm, margins entire, (pubescent as petiole, apex acute to subacute, trichomes simple and/or branched), surfaces pubescent, abaxially with simple trichomes, to 1 mm, and stalked, 2-4-rayed ones, 0.1-0.5 mm, adaxially with simple trichomes, 0.4-1 mm, (sometimes glabrous). Cauline leaves 0. Racemes 2-8-flowered (congested), ebracteate, slightly elongated in fruit; rachis not flexuous, pubescent as stem. Fruiting pedicels divaricate to ascending, straight or slightly curved upward, 1.5-4 mm, pubescent as stem or trichomes branched. Flowers: sepals ovate, 1.8-2.3 mm, pubescent, (trichomes simple with fewer, short-stalked ones); petals pale yellow, narrowly spatulate to oblanceolate, 2.5-3 × 0.8-1.5 mm; anthers ovate, 0.2-0.3 mm. Fruits often obovate, plane, slightly flattened, 5-10 × (3-)3.5-5 mm; valves glabrate or sparsely pubescent, 0.05-0.2 mm; ovules 8-16(-20) per ovary; style 0.05-0.15 mm. Seeds ovoid, 1.1-1.6 × 0.7-1 mm. 2n = 32.

Flowering Jun-Aug. Damp rocky slopes, tundra, swales, dry silt plains; 0-1000 m; Greenland; N.W.T., Nunavut; Alaska; Europe (Norway [Svalbard], Russia); e Asia (Russian Far East, n Siberia).

O. E. Schulz (1927) recognized five varieties within Draba pauciflora, of which four were listed from North America. Schulz’s concept of D. pauciflora encompassed multiple taxa that we recognize as separate species, including D. micropetala and D. subcapitata. C. L. Hitchcock (1941) and R. C. Rollins (1993) did not mention D. pauciflora; the latter (and G. A. Mulligan 1974b) referred the North American material to D. adamsii.