Solorina spongiosa is a lichen that is native to California.
California Rare Plant Rank: 2B.2 (rare, threatened, or endangered in CA; common elsewhere).
[Wikipedia] Naming, Genus Change: It was first formally described as a new species by the Swedish lichenologist Erik Acharius as Collema spongiosum. Italian botanist Martino Anzi transferred it to the genus Solorina in 1862. (link added by Mary Ann Machi)