Northern Prairie Wildlife Research Center
It is likely that smallflower wallflower can be found in every county in North Dakota. The plant also occurs from Nova Scotia to British Columbia, south to Missouri and Arizona at elevations up to 7,000 feet.
Smallflower wallflower is an erect perennial. Stems are usually single, but sometimes a plant will have several. Typical North Dakota specimens are only about 12-18 inches tall, but those from more southerly areas reach nearly three feet. Plants are branched on the upper one-fourth and roughened with short hairs. Leaves are narrow and about one or two inches long, entire or with a few shallow teeth or lobes. The tiny yellow flowers are only about one eighth inch wide. Seedpods are slim and about one inch long.
Look for smallflower wallflower from mid June to mid July in dry native prairie. Most plants can be found where grazing is light or moderate. A closely-related European Erysimum contains erysid, an active substance used for certain heart remedies in the Ukraine, but I found no mention of any economic uses for the species dealt with here.
This plant is placed in the mustard family (Brassicaceae). Many of the estimated 2,500 species in this family have been developed into food plants such as cauliflower, radish, turnip, and rutabaga, as well as many ornamentals. However, other mustards are troublesome weeds well known to North Dakota farmers. The family gets its name from brassica, the Latin name of the cabbage. The generic name Erysimum stems from the Greek eryomai meaning "help" or "save," from the supposed medicinal properties of some species claimed by the early European herbalist-physicians. There are about 80 species of Erysimum, mostly from Eurasia. The specific name inconspicuum means "inconspicuous" in botanical Latin, possibly in reference to the tiny, barely-noticeable flowers.
Smallflower wallflower was first described for science in 1871 by Sereno Watson (1826-1892), critical student of western American plants.