Clypeococcum D. Hawksw., J. Linn. Soc., Bot. 75: 196 (1977).
MycoBank number: MB 1114; Index Fungorum number: IF 1114; Facesoffungi number: FoF 08783; 9 morphological species (Species Fungorum 2020), 2 species with molecular data.
Type species: Clypeococcum cladonema (Wedd.) D. Hawksw., Bot. J. Linn. Soc. 75(2): 197 (1977).
≡ Lecidea cladonema Wedd., Bull. Soc. bot. Fr. 21: 345 (1874).
Notes: According to Hawksworth and Diederich (1988), this genus shares some characters with Polycoccum, but differs by hyphal rather than pseudoparenchymatous ascomatal walls, thickened around the ostiole, and by the ascomata occurring in groups united by a common clypeus. In phylogenetic tree of Ertz et al. (2015), Clypeococcum represented by C. placopsiiphilum and C. psoromatis is paraphyletic among Polycoccum. Ertz et al. (2015) noted that the long branches within Polycoccaceae clade showed the fast-evolving contrasting with low morphological variability, which results in few phenotypic characters useful for the recognition of different genera (Ertz et al. 2015). Clypeococcum is however included in Polycoccaceae but its placement will need to be confirmed by molecular data of type species. Fourteen epithets and 9 epithets of Clypeococcum are listed in Index Fungorum (2020) and Species Fungorum (2020), respectively, while sequence data are available for two species.
Species
Clypeococcum cladonema