Flowers: small; clustered in a long raceme. Calyx: of four sepals that fall early. Corolla: of four cruciferous petals. Stamens: six, two of which are shorter than the others. Pistil: one. Pods: triangular; notched at the apex; two-valved. Leaves: those of the base, clustered, incised; those of the stem, arrow-shaped, partly clasping. Stem: branching.
These insignificant little flowers crop out with much persistency along the wayside. Their generic name is derived from the pouch-like shape of their seed-pods. The plants are widely distributed all over the globe.