Northern Prairie Wildlife Research Center
It is unusual that records of Drummond's rock cress are restricted to northern and western North Dakota, for the overall range of the plant extends from Labrador to British Columbia south to Delaware, New Mexico, and California at elevations up to 11,000 ft. Botanists may merely have overlooked the plant when collecting in our southeastern counties.
Drummond's rock cress is a biennial (lives for two years) up to three feet tall, with simple or branching stems. The three-inch-long leaves are spoon shaped and most numerous at the base of the plant, but many narrower leaves also grow on the stem. The pink-to-purple flowers are about a half inch long and form in loose spikes at the tops of the stems. Fruits are straight thin "pods" (silques) up to three inches long that stand erect on thin pedicels. The tiny seeds have a thin wing around their margins.
Look for Drummond's rock cress during July and August on rocky or gravelly soils in ungrazed or lightly grazed areas. I could find no references to economic uses of this plant.
Drummond's rock cress is a member of the mustard family (Brassicaceae), some of whose 2,500 members have been developed into food plants such as cauliflower, radish, turnip, and rutabaga, as well as many ornamentals. However, other mustards are troublesome weeds. The family gets its name from brassica, the Latin name of the cabbage.
Carl von Linne (Linnaeus), the Swedish father of modern plant taxonomy, named the genus in 1753, purportedly after some mustard found in Arabia. There are about 100 species of Arabis in the north temperate zone. The species was named in 1866 in honor of its discoverer, Thomas Drummond, by the United State's preeminent botanist Professor Asa Gray (1810-1888) of Harvard University. His botanical manual for the northeastern states, first printed in 1848, has gone through eight editions.