isidiomorph (noun, pl. isidiomorphs) – a structure similar in shape and appearance like an isidium but not of the same function or internal organization. The term isidiomorphs includes thallus surface structures that are superficially similar to isidia, but have a different anatomy or function, such as dactyls or pseudoisidia. The following surface structures are here referred to as isidiomorphs: dactyl, foliaceous phyllocladium, fragmentation region, granuliform phyllocladium, isidioid tip, phyllidium, phyllocladium, pseudoisidium. This is:part of thallus surface. Kind of:upper surface structure.