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 (emerging between the petals) 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.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Draba crassa