Perennial Pepperweed (broad-leaved peppergrass, tall whitetop, Virginia pepperweed) Brassicaceae (= Cruciferae), the mustard family
BACKGROUND: Perennial pepperweed is native to southern Europe and western Asia. It spreads by seed and creeping roots under many different environmental conditions.
DESCRIPTION: Perennial pepperweed grows up to 6 feet tall and has basal leaves that are lance shaped, have long petioles, are up to 12 inches long, and are covered with a waxy layer. Stem leaves are smaller and have shorter petioles, but don’t clasp the stem. Leaves have a prominent, whitish midvein. Flowers are white, less than 1/6 inch wide, and develop in dense, rounded clusters at the branch tips from early summer until fall. Fruits are roundish, slightly hairy, measure 1/16 inch in diameter, and contain 2 tiny seeds.
DISTRIBUTION: Perennial pepperweed is widely scattered throughout the U.S. and in many Idaho counties.
CONTROL: No biological control agents are available for perennial
pepperweed, but herbicides are available to provide control.
© 1999 University of Idaho: Text and photographs for these pages from Idaho’s Noxious Weeds, by Robert H. Callihan and Timothy W. Miller (revised by Don W. Morishita and Larry W. Lass).
Please contact: Ag Publishing, University of Idaho, Moscow, Idaho 83844-2240; (208) 882-7982; [email protected]; or visit the UI Extension/CALS Publications and Multimedia Catalog website at www.cals.uidaho.edu/edComm/catalog.asp, for more information about this or other publications.
