Draba yukonensis A.E. Porsild
Family: Brassicaceae
Yukon Whitlow-Grass
Images
not available

Perennials; (short-lived); caudex simple or branched (with persistent leaf remains); not scapose. Stems branched, 0.4-2 dm, pubescent throughout, trichomes simple, 0.3-1.2 mm, and 2-6-rayed, 0.05-0.6 mm. Basal leaves rosulate; subsessile; blade oblanceolate to narrowly so, 0.3-1 cm × 0.5-2 mm, margins entire, (ciliate, trichomes simple, to 1.3 mm), surfaces pubescent, abaxially with (rigid), simple and 2-rayed trichomes, 0.4-1.2 mm, sometimes with short-stalked, 3-6-rayed ones, 0.1-0.3 mm, adaxially with simple trichomes. Cauline leaves 1-3; sessile; blade ovate to oblong, margins entire, surfaces pubescent as basal. Racemes 5-20-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. Fruiting pedicels erect to ascending, straight, 0.5-3 mm, pubescent as stem. Flowers: sepals ovate, 1.2-1.6 mm, pubescent, (trichomes simple and 2-4-rayed); petals white, spatulate, 1.5-2 × 0.7-0.8 mm; anthers ovate, ca. 0.2 mm. Fruits ovoid to oblong, plane, not flattened, 2-5 × 1.5-2 mm; valves pubescent, trichomes short-stalked, 4- or 5-rayed, 0.05-0.3 mm; ovules 36-52 per ovary; style 0.1-0.3 mm. Seeds oblong, 0.6-0.8 × 0.3-0.4 mm.

Flowering late May-Jun. Open stony ridges on ancient beach in grassy areas and aspen stands; of conservation concern; ca. 600 m; Yukon.

Draba yukonensis is known only from Kluane National Park, southwestern Yukon Territory.