… by genus: Lecanora
Greek: lekanon (little bowl) and ora (form, beauty), referring to the apothecia. This is a varied and colourful group. They are all crustose and are referred to as the rim-lichens because of the round cup-like apothecia. Photobiont is Trebouxia or Pseudotrebouxia. Paraphyses branched at the tip. Spores simple and colourless. Isidia and cephalodia are absent. The thallus often has a crazy-paving arrangement (areolate) with a placodioid (lobed) edge. They lack isidia and cephalodia. Apothecia are their primary reproductive structure. The ascospores are simple and colourless. About 300 species are known worldwide. Forty eight species have been recorded in Ireland.