Individual flowers, about ½ inch wide, are formed of 5 dissimilar petals, usually magenta red, sometimes other shades from rose to purple. The banner bends back slightly and carries markings of lighter color near its base; the 2 lateral petals are plain and angle forward; the 2 lower petals form a narrow keel. Numerous flowers, attached at the calyx base along the upper third of a naked stem, form a showy spike 10 inches or more tall, several of which rise from one root crown. Leaves, pinnate, with numerous green leaflets, rise also from the root crown and are about half the height of the flower spikes. Grows in foothills and higher parts of plains zone. Blooms May-July.

The many members of the pea family going by the names of loco, vetch, milk vetch, etc., are usually considered crass weeds and are in disrepute because some of them are poisonous to stock. They often grow in soil containing traces of selenium, and are doubly harmful in that case. Where other browze is good, animals usually leave the toxic ones alone, except the occasional horse that becomes “an addict” and is “locoed.” In spite of these obnoxious qualities, there are few plants that give more bright and decorative touches to the plains.