Pseudotrillium
 Pseudotrillium is a proposed monotypic genus of flowering plants containing the single species Pseudotrillium rivale which is known by the common name brook wakerobin. The genus was proposed in 2002 on the basis of morphology and molecular evidence that suggest the plant should no longer be included in genus Trillium.This species is endemic to the Siskiyou Mountains of southern Oregon and northern California usually on soils of ultramafic origin such as serpentine.