Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Perennial pepperweed, Extension, University of Nevada, Reno, Field Guide

Stem

Up to 6 ft. tall, semi-woody, waxy and lacks hair (glabrous); many stems can arise from each crown; often branched near top; branches arise from leaf axils

Leaves

Alternate, oval to lance-shaped, mostly 3-12 in. long, 1-3 in. wide, green to gray-green, lack hair and waxy; edges (margins) smooth to toothed and can also be curled; leaf bases DO NOT clasp stem; lower leaves larger than upper leaves

Flower

Small and white with 4 petals; arranged in dense clusters at the tips of stems
Seed pods are round, flattened, less than 0.1 in. diameter, usually covered with hairs; each seed pod has 2 chambers, each with 1 seed

Root

Creeping root system

Photo of perennial pepperweed bush with white flowers

Other

Grows best on moist sites; often found in floodplains, pastures, meadows, hay fields and along waterways; known to occur throughout Nevada
Perennial; reproduces by roots and seed
Also known as tall whitetop

Photo of a field of perennial pepperweed

Control

Mowing, digging, tillage, burning and grazing established stands is NOT effective
Apply chlorsulfuron, imazapic, imazapyr, or metsulfuron to actively growing plants through early-bloom; 2,4-D and glyphosate at bud to flower can be effective if repeated for several years

Learn more about the author(s)

Heidi Kratsch

Also of Interest:

Nevada Noxious Weed Field Guide – Perennial pepperweed