Perennial Pepperweed

General: Perennial pepperweed is a herbaceous perennial in the Mustard family (Brassicaceae). In medieval Britain, the seeds were known as “poor man’s pepper” and the roots were a substitute for horseradish.

Flowers: White, four-petal flowers that form dense clusters at the end of branches.

Stems: Are branched, erect, waxy and grey-green, occasionally with red spots. Stems can grow up to 2 m tall and are woody at the base.

Leaves: Rosette leaves are oval or oblong with smooth or jagged edges. Stem leaves attach directly to the base of the plant in an alternate arrangement, and are lance-shaped with smooth to toothed margins. Leaves become smaller towards the top of the stem.

Seeds: Are small (1.5 mm), flat, and round or oval-shaped. Each seed pod contains two seeds.

Roots: Are deep, minimally branched, and enlarged at the soil surface, forming a semi-woody grown.

Perennial pepperweed is native to southeastern Europe and southwestern Asia. It is believed to have been introduced to North America in a shipment of sugar beet seeds.

The plant tolerates a variety of soil characteristics, such as clayey, loamy, sandy or silty. It is also tolerant of calcium-rich soils. Perennial pepperweed invades flood plains, irrigation structures, pastures, wetlands, riparian areas, roadsides, dry hillsides and residential sites.

Ecological: 

• Decreases native biodiversity by creating a monoculture.
• Increases soil salinity.
• Decreases availability of suitable nesting habitats.

Economic:

• Reduces forage quality and makes horses and cattle sick by preventing sodium and water retention.