The genus Picoa is here revisited after obtaining new molecular and morphological data. Morphological features of type material and other historical collections of P. juniperi and P. lefebvrei were studied and compared with recent collections obtained from several European, African, and Asian countries. Genetic studies employing ITS rDNA, as well as 28S rDNA and the RPB2 gene, were conducted on modern samples. As a result, 19 taxa are identified, 17 of which are new to science. Detailed descriptions of all species are provided, including macro- and micro-photographs, and an identification key. The phylogenetic structure of the genus is discussed, and the main clades are described in the following new sections: Picoa sect. Communes, sect. Juniperi, sect. Lefebvreorum, sect. Microsporae, and sect. Puenteorum. Finally, the boundaries of the genus Picoa are evaluated by comparison with the sister genera Geopora, Sepultaria, and Terracavicola.
Alvarado et al. (Tue,) studied this question.