Physcia rhizinata is a species of corticolous (bark-dwelling), lichenized fungus in the family Physciaceae.
It is a "typically fertile species lacking asexual propagules" commonly mistaken for P. stellaris due to their physical similarities.
[1] It has a close evolutionary relationship with P. occidentalis despite being morphologically dissimilar.
[1] Physcia rhizinata is only known to be found in California.
[1] At least one specimen has been located in a canyon of the South Cow Mountain OHV Management Area owned by the Bureau of Land Management in a canyon live oak forest.