Acantholichen is a fungal genus in the family Hygrophoraceae. A monotypic genus it contains a single species, the basidiolichen Acantholichen pannariodes, discovered originally in Costa Rica in 1998. This species has a bluish, gelatinous thallus, and a fine, white powdery bloom covering the hairy upper surface; this surface is said to resemble "an unshaven chin".