Draba cana
Draba yukonensis
Brewer's Draba, canescent Draba, canescent whitlow-mustard, cushion Draba, hoary Draba, hoary whitlow-grass, lance-leaf Draba, lance-leaf whitlow-grass
Yukon whitlowgrass
unbranched or branched distally, (0.6–)1–3(–3.8) dm, pubescent throughout, trichomes simple, 0.5–1mm, with 4–10-rayed ones, 0.05–0.2 mm (mostly branched on basal parts).
branched, 0.4–2 dm, pubescent throughout, trichomes simple, 0.3–1.2 mm, and 2–6-rayed, 0.05–0.6 mm.
rosulate; petiolate;
petiole ciliate throughout;
blade linear to oblanceolate or oblong, (0.5–)0.8–2(–3.5) cm × 1.5–4(–11) mm, margins entire or dentate, (base and apex ciliate, trichomes simple, 0.3–0.8 mm), surfaces pubescent with short-stalked, 4–12-rayed trichomes, 0.1–0.3 mm.
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.
3–10(–17), (not overlapping);
sessile;
blade lanceolate to ovate or oblong, margins entire or dentate, surfaces pubescent as basal (adaxially with simple and forked trichomes near blade base).
1–3;
sessile;
blade ovate to oblong, margins entire, surfaces pubescent as basal.
(10–)15–47(–63)-flowered, basally bracteate, often considerably elongated in fruit;
rachis not flexuous, densely pubescent, trichomes 4–10-rayed (0.05–0.2 mm), and fewer simple ones.
5–20-flowered, ebracteate, considerably elongated in fruit;
rachis not flexuous, pubescent as stem.
sepals (green or lavender), oblong to ovate, 1.5–2 mm, pubescent, (trichomes simple and few-rayed);
petals white, oblanceolate to spatulate, 2.3–3.7(–4.5) × 0.7–1.7 mm;
anthers ovate, 0.1–0.2 mm.
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.
suberect or ascending, straight, 2–5(–10) mm, pubescent as rachis.
erect to ascending, straight, 0.5–3 mm, pubescent as stem.
(subappressed to rachis), linear-lanceolate to linear or, rarely, ovate-oblong, slightly twisted or plane, flattened, (5–)6–11 × 1.5–2(–2.5) mm;
valves pubescent, trichomes short-stalked, 3–7-rayed, 0.05–0.3 mm;
ovules 28–48 per ovary;
style 0.1–0.6 mm.
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.
ovoid, 0.5–0.7(–0.9) × 0.3–0.5 mm.
oblong, 0.6–0.8 × 0.3–0.4 mm.
= 32.
Draba cana
Draba yukonensis
The limits of Draba cana have long been confused, and the species was treated as a synonym of the Himalayan D. lanceolata Royle (M. L. Fernald 1934; C. L. Hitchcock 1941) or as a variety of the western North American D. breweri (R. C. Rollins 1993). However, G. A. Mulligan (1971) clearly demonstrated that all three are distinct and should be maintained. Some Utah plants corresponding to the type of D. valida have shorter and wider oblong-ovate fruits. In all other aspects, they are indistinguishable from D. cana. Additional studies are needed to establish whether such plants should be formally recognized.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Draba yukonensis is known only from Kluane National Park, southwestern Yukon Territory.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
MI Flora, 
PNW Herbaria, 
SW CO Wildflowers 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
