sect. Cardaria (Desv.) DC.
Perennial herbs often stoloniferous, branched mostly from the base, erect or suberect, pubescent with simple or forked, appressed hairs, rarely glabrous, leafy. Basal leaves oblong-elliptic, stalked; cauline leaves sessile, lanceolate to ovate-oblong, with somewhat narrowed base, auricled (rarely auricle suppressed), amplexicaul, ± dentate, sometimes almost entire. Racemes and flowers similar to Lepidium but nectar glands different; not fragmentary, middle often joining the laterals and narrow, lateral extended and often in fused pairs. Ovary 2-4-ovuled, elliptic to suborbicular, with usually equally long style, bilocular, glabrous or minutely pubescent. Siliculae ovate, subglobose to orbicular, inflated to laterally flattened or subcompressed, bilocular indehiscent; valves ± membranous, convex to flattened, glabrous to pubescent, reticulately veined to almost smooth; septum present, windowed, narrow, membranous, not veined;seed 1 (-2) maturing in fruit (and thus usually making the fruit oblique or asymmetrical), ellipsoid, pendulous, reddish-brown; radicle incumbent.
4 or 5 species in Europe and Asia.
Hymenophysa C.A.Mey. (1831) is, no doubt, congeneric with Cardaria Desv. (1814) as treated by Rollins (l.c.) and Hedge (l.c.). Its proper place would have been under the tribe Lepidieae instead of the tribe Euclidieae, because of the ± membranous valves. Morphological and fruit similarity indicates that it should be merged with Cardaria. Nectar glands, structure and behaviour of siliculae, and different form of embryo, leave no doubt that Cardaria should be treated as a genus separate from Lepidium.