Trillium ovatum, the Pacific trillium, western trillium, western wakerobin, or western white trillium, is a member of the Trilliaceae family, or sometimes included within the Liliaceae or Melanthiaceae. It occurs in parts of the western United States and western Canada, usually in rich forest. In the northern part of its range, which includes southern British Columbia, extreme southwestern Alberta, Washington, Oregon and east to Montana, Wyoming and northern Colorado, it often grows under Douglas-fir. Other trees which frequently shade this trillium include grand fir, western red cedar, and western hemlock; bigleaf maple, red alder and Sitka spruce join in near the coast. Near California shores, it is common under coast redwood. Associated understory plants include swordfern, vanilla leaf, violets, redwood sorrel and salal.