Draba sphaeroides

Perennials; (cespitose, densely pulvinate); caudex branched (branches often tangled with persistent leaf remnants, prostrate, slender, sometimes terminating in sterile rosettes); scapose. Stems unbranched, (0.2-)0.3-0.8 dm, sparsely pubescent proximally, glabrous distally, trichomes usually 2- or 3-rayed, rarely some simple, 0.1-0.25 mm. Basal leaves not rosulate; subsessile; petiole margins not ciliate; blade oblanceolate to oblong or elliptic, 0.3-0.8(-0.9) cm × (1-)1.5-3(-4) mm, margins entire, (not ciliate), surfaces usually pubescent, rarely both surfaces glabrous (except margin), with stalked, 2-4-rayed trichomes, 0.07-0.4 mm (or, rarely, trichomes mostly simple and 2-rayed adaxially). Cauline leaves 0. Racemes (3-)5-11(-14)-flowered, ebracteate, slightly elongated in fruit; rachis not flexuous, glabrous or sparsely pubescent as stem. Fruiting pedicels divaricate-ascending, straight or curved upward, (sometimes slightly expanded basally), 3-8 mm, usually glabrous, rarely sparsely pubescent, trichomes simple and 2- or 3-rayed. Flowers: sepals broadly ovate, 1.7-2.5 mm, glabrous or sparsely pubescent, (trichomes simple and short-stalked, 2- or 3-rayed); petals yellow, spatulate, 2.7-4 × 1.5-2.2 mm; anthers ovate, 0.4-0.5 mm. Fruits broadly lanceolate to ellipsoid or ovoid, plane, inflated at least basally, (2.5-)3.5-7(-8) × (1.5-)2-3.5 mm; valves glabrous or sparsely pubescent, trichomes simple and short-stalked, 2(-4)-rayed, 0.07-0.2 mm; ovules 4-10(-12) per ovary; style 0.3-1(-1.3) mm. Seeds oblong, 1-1.5 × 0.8-1 mm. 2n = 20.

Flowering Jun-Aug. Rock outcrops, talus, soil pockets on rocky slopes; of conservation concern; 2500-3300 m; Nev.

Draba sphaeroides is closely related to D. pedicellata; the two are easily distinguished using the characteristics discussed by M. D. Windham (2004). The species is known from Elko County (East Humboldt, Ruby and Jarbidge mountains) in northeastern Nevada.