- Control Strategies
- Infestation Map
PERENNIAL PEPPERWEED — Lepidium latifolium L.
Brassicaceae — (Mustard family)
The narrow serrated basal leaves about 12 inches long arise from seed or existing robust roots, they are green or grayish and waxy, lance shaped, attaching to the root by the light colored mid vein. The leaves grow alternately and become smaller and fewer upwards on the stem.
Numerous woody stems grow to be 3ft. or more tall and are topped by airy clusters of tiny white 4 petal flowers.
Each flower develops into an oval pod containing two small brownish seeds.
Perennial Pepperweed is hard to control because the leaves are waxy and resist chemical control, and because it easily grows from deep perennial roots, from creeping underground root buds, and from the thousands of seeds from each plant. The plant readily spreads from wet or waste areas, ditches, or roadsides into cropland, range or meadows and is not grazed by either livestock or wildlife.
Perennial Pepperweed is the fastest spreading weed in Fremont County.
The following is courtesy of Weeds of the West:
Perennial pepperweed is similar to whitetop, however, it is taller. Perennial pepperweed stands one to over three feet high with a heavy, sometimes woody, crown. The leaves lanceolate, bright green to gray-green, the lower leaves are oblong with toothed margins and a waxy texture, basal leaves larger than upper leaves; inflorescence a raceme. The upper leaves do not clasp the stem as whitetop does. Flowers are white, in dense clusters near ends of branches, very small; fruit a silicle; seeds two per fruit, rounded, flattened, slightly hairy, about 1/16 inch long and reddish-brown. Flowering occurs from early summer to fall.
Perennial pepperweed is a native of Southern Europe and Western Asia but is now found in many parts of the United States. It has been declared noxious in a number of Western states. The deep-rooted perennial plant with extensive, vigorous creeping root system reproduces by root stalks and also by seed. Perennial pepperweed grows in waste places, riparian areas, ditches, roadsides, pastures, cropland and disturbed areas. The waxy layer makes this perennial difficult to control.
Nonstandard name: broad-leaved peppergrass, tall whitetop, Virginia pepperweed.
Growth Habit: Erect perennial, numerous stems, spreading by seed and deep-seated rootstocks.
Leaves: Alternate, lance shaped, bright green to gray-green, waxy, smooth to toothed margins, basal leaves larger than upper leaves.
Stems: Branched, smooth, waxy, 1-3 feet tall.
Flower: Raceme of small white flowers in dense clusters near branch ends.
Roots: Deep-seated and spreading.
Seeds: Small, rounded, flattened, slightly hairy, 1/16 inch long, reddish brown.
Other: Deep roots make it difficult to control.
(Courtesy of Weeds of the West)