[Wikipedia] Range, Habitat, Ecology, Threats: Erythronium revolutum is native to western North America, from coastal Northern California to British Columbia, including Vancouver Island.[3] It grows in wet areas in forests and along stream banks.[4] Ecology Erythronium revolutum is most abundant within 100 miles (161 km) of the coast, at altitudes of less than 1000 m.[3] The plant is found in moist places such as streambanks, bogs, and wet redwood and mixed evergreen forest understory.[2][3] It is slow-growing, taking 5 to 7 years to form a flowering size bulb,[5] and therefore is slow to establish in new locations. These habitats are threatened in the wild and in addition, E. revolutum may be threatened by collection for horticulture and soil compaction by forestry machinery.[5] (link added by Mary Ann Machi)