Lepidium latifolium is a perennial that can grow from 1-5 ft. (0.3-1.5 m) in height. In the late fall to early spring a rosette of leaves develops with 4-12 in. (10-30 cm) long and 1-2 in. (2.5-5 cm) wide, toothed leaves. Plants emerge from thick, minimally branched roots or semi-woody crowns. Individuals remain as a rosette for several weeks before the stem elongates.
Foliage
Rosette leaves are long petiolate. Cauline (stem) leaves are alternate, 1-3 in. (2.5-7.6 cm) long and oblong.
Flowers
Flowering occurs in the late spring to summer, when flat, dense clusters of flowers develop at the apex of the flowering stem. Individual flowers are 4-petaled and white.
Fruit
The fruit is a round to oval, hairy capsule that is 0.06 in. (1.5 mm) in diameter. It contains a single seed.
Ecological Threat
Lepidium latifolium invades coastal wetlands, riverbanks, marshes, rangelands, and roadsides. It can form dense monocultures that can increase in size over time crowding out native species. This plant was accidentally introduced into the United States around 1936 as contaminant in seed. It is native to Eurasia.