Whitetop is an herbaceous perennial, spreading mainly by creeping rhizomes producing root shoots. It also produces hundreds of seeds per plant. Also referred to as Hoary cress; Hoary meaning grayish and cress for its use as a salad green in medieval Europe. Draba is the most common of the three species in far Eastern Oregon and Southwest Idaho. Draba seed pods are heart shaped. Leaves are 1 to 3 inches long with slightly toothed margins near the tip. White flowers develop at stem ends and form a canopy, each has 4 petals opposite. Very closely related to broccoli and in fact has a similar taste but with a spiciness and heat. The seeds are very hot and spicy as you would expect from the mustard family.

Not particularly competitive and will not usually invade healthy pasture. Difficult to control once it is established. 2,4-D with Dicamba works with repeated treatments over several years. Chlorsulfuron (Telar) and Metsulfuron methyl (Escort) are also very effective. They both have some residual effect, sprayed at the correct time and you may gain 2 seasons of control, with quickly diminishing plant density. Extremely difficult to remove by hand or mechanical methods, persistence will eventually payoff.
‍
Modified from Selected Noxious Weeds of Eastern Oregon, Gary Page, Malheur County Weed Inspector.