Lepidium chalepense L.
Lens-Podded Hoary Cress
Family - Brassicaceae
Stems - Erect, densely short-hairy.
Stem and leaves.
Leaf - Densely short-hairy. Lower leaves petiolate. Upper leaves clasping stem, auriculate, ovate to oblanceolate, coarsely and irregularly toothed.
Inflorescence - Flat-topped panicles.
Flowers - Petals white, 2.5-4.5 mm long, exceeding sepals. Stamens 6. Styles 1.0-1.8 mm long.
Fruits - On 5-10 mm stalks, 3.0-5.5 mm in diameter, slightly flattened to inflated, rounded to truncate at base, glabrous, unwinged.
Flowering - April - July.
Habitat - Roadsides, open, disturbed areas.
Origin - Native to Eurasia, widely introduced in U.S.
Other info. This species is very similar to Lepidium draba, which has fruits which are more flattened and cordate at the base. These plants can form dense rhizomatous colonies, conspicuous in flower with shining white inflorescences. The hoary cresses are considered pests in some western states.
Photographs taken near West Alton, St. Charles County, MO, 4-29-2016, and near Labadie, Franklin County, MO, 4-19-2017 (SRTurner).