Cardamine diphylla is native across the eastern United States and Canada, a quiet perennial of rich deciduous woodland floors that has been navigating the rhythms of the forest canopy for a very long time. The species name diphylla is Greek for two-leaved, referring to the paired stem leaves that emerge with the plant in spring, broad and coarsely toothed, reaching eight to sixteen inches tall. The flowers appear in a loose cluster at the stem's end from mid-April to mid-May — white to pale pink, small, and cross-shaped in the classic mustard-family arrangement. Long, slender pods follow, splitting open four to five weeks after bloom to release their seeds. By summer the plant is gone entirely, dormant underground in its rhizomes.

This disappearing act is both the plant's greatest trait and its main garden challenge. The space it occupies in spring is empty by July, so companion planting under the same canopy — ferns, hostas, other woodland perennials — is necessary to keep the picture coherent through the season. It makes an excellent groundcover under Cornus florida, whose scale and timing align well. The rhizomes spread slowly, and the plant naturalizes without becoming aggressive. Two species of butterfly use it as a host plant: the West Virginia white and the falcate orange-tip. Specialized Andrena bees collect its pollen. Propagation by rhizome division, taken when dormant and handled carefully to avoid breaking the fragile roots, is more reliable than seed.