Lepidium virginicum is an annual or biennial, C3 herb (Ludwig et al. 2010), 10-50 cm tall, taprooted, base of stem sometimes purple, simple to freely branched from upper leaf axils.
Leaves alternate, those of basal rosette 2-10 cm long, 0.5-2 cm wide, inversely lance-shaped (oblanceolate), margin sharply toothed to deeply lobed; stem leaves narrow, small, tip pointed, gradually narrowed to base, often becoming sessile (Radford et al. 1968); withering upward as plant flowers.
Flowers white, petals 4, to 0.2 cm long, 0.1 cm wide, or sometimes none (Yatskievych 2006), sepals greenish, cupped, alternating with, and about as long as petals, stamens 2-4, ovary superior, rounded,
flattened, 0.1 cm wide; inflorescence of numerous, upright, terminal racemes to 10 cm long, tips crowded, head-like in flower, becoming elongate below as fruit develops; blooms and fruits May-Nov. Probably self-fertile but visited by a number of insects including Syrphid flies, small carpenter bees, Halictine bees, some wasps, and flies (Hilty 2006).
Fruit dry, 0.3- 0.4 cm wide, flat, narrowly winged, circular, slightly notched at apex, seeds 2, narrowly winged, 0.2 cm wide, brown, one on each side of midrib (Radford et al. 1968); fruits July-Nov.
Wetland status: FACU-.
Frequency in NYC: Common.
Habitat: Disturbed, open areas, moist to dry soil, sand, fill, roadsides, fields.
Notes: Winter plant with silvery capsule septum persistent on pale tan stems (Levine 1995). Seeds eaten by some birds and rodents (Martin et al. 1951). Mature fruit with peppery taste, edible (Yatskievych 2006). Foliage and other plant parts fed upon by the caterpillars of some butterflies and moths. These include the cabbage white, Pieris rapae, checkered white, Pontia protodice, snout moth, Eustixia pepula, and the purple-backed cabbage worm moth, Evergestis pallidota. Rabbits and groundhogs may consume small plants during the spring when few other plants are available, although the peppery foliage probably repels most mammals (Hilty 2006). An invasive, non-native on some Pacific Islands (USDA Forest Service 2006).