From Oregon Flora, Gardening with Natives:
This unique wildflower emerges in spring, its distinctive 3-petaled white infloresence brightening the deep shade and dark colors of the moist forest floor. The white petals can fade to pink or even red as they age. Single flowers bloom on a short peduncle, rather than being sessile as in other trilliums, and are framed by three sepals and three broad leaves resulting in a pleasingly balanced composition. It grows slowly, spreading from rhizomes and does best in moist acidic soils with high organic matter and dappled sun to full shade. Slugs love it.