The genus Trillium was traditionally placed in the catch-all family Liliaceae (in the broad sense). More recently, mainly on the basis of DNA studies, the trilliums are placed in their own family. The genus contains plants with leaves that grow as sets of three and a rhizomatous root. There is a single flower per shoot, with three sepals and three petals. They are native to the Northern Hemisphere, found mainly in North America and in China. They occur in woodland settings in shade or partial shade.

Trillium recurvatum is native to the northeastern USA. It has very attractive mottled foliage.

For more on some of the species of Trillium:

Germination of Trillium Seeds, see: Germination

For a glossary of specialized terms applying to Trillium: