Pseudotrillium

Pseudotrillium is a monotypic genus in the bunchflower family Melanthiaceae. Its sole species, the flowering plant Pseudotrillium rivale, is commonly known as the brook wakerobin. It is endemic to the Siskiyou Mountains of southern Oregon and northern California. The Latin specific epithet rivale means "growing by streams", a reference to a preferred habitat....read more on Wikipedia.