Chorispora tenella is a species of plant in the mustard family known by several common names, including purple mustard, blue mustard, musk mustard, and crossflower. This mustard is native to Eurasia but is well known in other parts of the world, particularly in temperate regions, as an introduced species and a noxious weed. This is an annual herb reaching a maximum of half a meter in height and covered abundantly in sticky foliage.
Invasive in Colorado, Nevada, and Wyoming.