Cryptothecia
Cryptothecia is a genus of white to greenish crustose lichens that grow on bark, wood, or leaves. in tropical or subtropical areas worldwide. It has a conspicuous prothallus that develops around its periphery which can be bright red in some species, hence the common name wreath lichen. The main vegetative body lacks a cortex.
Two species have been described in North America. At least one species, Cryptothecia rubrocincta, has been used in Brazil as a source of dye.Gallery
