Draba crassa
Brassicaceae (Mustard Family)

Alpine. Scree. Summer.
Black Bear Pass, July 20, 2008.

With their bright yellow flowers and mass of bright green leaves, these tiny tufts are easy to spot on alpine scree.  They are rare and are found primarily in Colorado (in twenty counties), in two counties of Utah and Montana, and in four counties in Wyoming. 

The Draba genus was named by Linnaeus in 1753 and this species was named by Per Axel Rydberg in 1900 from plants he collected on Gray's Peak in 1895.  "Crassa" is Latin for "thick" and refers to the roots.

Draba crassa
Brassicaceae (Mustard Family)

Alpine. Tundra, scree. Summer.
Black Bear Pass, July 20, 2008.

Draba crassa
Brassicaceae (Mustard Family)

Alpine. Tundra, scree. Summer.
Black Bear Pass, July 20, 2008.

Seeds are glabrous (not hairy) and often twist, but the young green seed at the very bottom, center of the photograph is still straight.

Draba crassa
Brassicaceae (Mustard Family)

Alpine. Tundra, scree. Summer.
Black Bear Pass, July 20, 2008.

Leaves are long-petioled (as the leaf tilted in the center shows), often red margined, lightly hairy on the edges, smooth on the surfaces, prominently mid-veined with a slight inward folding, and in a dense mass.

The flower stem (across the middle of the photograph) is lightly hairy.