Lepidium species - Swine-cresses and Pepperworts

Mostly have pinnate or simple leaves, hairless or simple hairs. All have winged oval fruits, white flowers in a raceme. Look at the fruits, shape and length of style - does it protrude from the fruit's circumference.

Lepidium didymum Lesser Swine-cress. all leaves pinnate, whole plants strongly scented when crushed. Stems usually hairy. Petals shorter than sepals or absent. Pedicels longer than fruit and fruit has a very short included style. Commoner

Lepidium coronopus Swine-cress  all leaves pinnate, whole plants unscented when crushed. Stems glabrous. Petals longer than sepals. Pedicels shorter than fruit and fruit has protruding style.

Lepidium campestreField Pepperwort  basal leaves soon withering, stem leaves triangular, stalkless, simple, toothed, softly hairy and clasping with pointed basal lobes. Flowers in racemes with 6 stamens and yellow stamens. Fruit with notch and style not projecting beyond. There are small vesicles on the fruit. 

Lepidium heterophyllum Smith's Pepperwort like campestre but violet anthers and style clearly beyond the notch. There are no vesicles on the fruit. commoner

Lepidium draba Hoary Cress erect, glabrous. Patch forming with rhizomes. Basal leaves soon wither, but stem leaves have basal lobes which clasp the stem. Inflorescence is crowded, branched and tends to be flat-topped. Fruits unwinged with prominent style > 1.5mm (awaiting photos)

Lepidium sativum Garden Cress an infrequent bird-seed or cultivation casual. Upper and lower stem leaves gradually different, lower leaves deeply pinnatifid and no leaves clasping the stem. Fruit >4.5mm and longer than the pedicel, broadly winged, apically deeply notched with a shorter style.

Lepidium virginicum Least Pepperwort Increasingly common street weed. Basal leaves, long stalked, pinnate to divided. Stem leaves increasingly entire becoming narrowly lanceolate. Inflorescence in long spikes, white petals twice s long as sepals. Fruit orbicular, narrowly winged above with shallow notch and a short style.

Other plants have a common name including ‘cress’ such as: Thale Cress, Water-cress, Bitter-cress, Yellow-cress and Winter-cress.