Perennial Pepperweed
(Lepidium latifolium)
Pedro Tenorio-Lezama, Bugwood.org
Also known as tall whitetop, this perennial weed was brought into the country as a contaminant of sugar beet seeds. It grows from 2 to 4 feet tall with white flowers in rounded clusters on the ends of the branches. Leaves are oblong and smooth with toothed edges and a white midrib. This plant uses its extensive root system to draw salts from deep in the soil.
The salt is then exuded from the leaves and is deposited on top of the soil where it can inhibit other plant growth. Pepperweed is usually found in moist areas such as wetlands, riparian areas, ditches and seasonally flooded areas. It can be found scattered throughout central to western Garfield County, with the largest infestation being along Parachute Creek.