Southwest Colorado Wildflowers, Erysimum

David Douglas collected the first specimens of this plant in "rocky places of the Columbia, near the sea; and at Puget Sound" (quote from Intermountain Flora). Douglas named the plant Cheiranthus capitatus in William Hooker's Flora Boreali-Americana, 1829. The plant was renamed Erysimum capitatum by Edward Greene in 1891. The plant has endured several dozen name changes since Douglas collected it.

There is still considerable disagreement about the name of and characteristics of this plant:

1) Both Weber and Intermountain Flora state that our widely distributed and highly variable common Erysimum is E. capitatum and that E. asperum is a plant of the plains, primarily differing from S. capitatum by having seed pods that are quite hairy and extending almost at right angles from the stem. E. capitatum seed pods are smooth and nearly vertical (almost parallel to the stem). Weber states that on the West Slope E. asperum exists only in the far northern counties.

2) Stanley Welsh, who almost always retains the plant names used by Intermountain Flora, takes a very different position and states that all of the Utah plants (and I infer, West Slope Colorado plants also) are E. asperum, i.e., E. capitatum is really E. asperum.

3) Based on the collections of Heil and O'Kane for their 2008, Flora of the Four Corners book, The Synthesis of the North American Flora recognizes both species in the Four Corners area.

"Erysimum", from the Greek "eryomai" meaning "help" or "save", refers to the centuries old belief that the plant had medicinal properties. Linnaeus named this genus in 1753.

"Capitatum" (Latin for "head", as in "decapitate’) refers to the rounded, head-shaped flower cluster.

Erysimum capitatum (Wallflower)
Brassicaceae (Mustard Family)

Semi-desert to alpine. Woodlands, meadows. Spring, summer.
Canyons of the Ancients National Monument, March 17, 2005.

This is a wide-spread, common, and highly variable species. It is a handsome plant often brightening, as in the first two pictures, the dry-brown duff under Junipers and Pinyons in the early spring. In the first picture, the plant is quite young and short but is already beginning to flower.

Erysimum capitatum ( Wallflower)
Brassicaceae (Mustard Family)

Semi-desert to alpine. Woodlands, meadows. Spring, summer.
Canyons of the Ancients National Monument, April 1, 2005.

Several weeks later, plants in the same area are over a foot tall and the spreading and then ascending seed pods (siliques) have begun maturing (just to the right of the curved leaf below center right).