Four new Pyrenula species from primary forests in the Guianas, South America, and their ascospore development

Four new species of the genus Pyrenula (Pyrenulaceae, Pyrenulales, lichenized Ascomycetes) are presented. They originate from primary forests in the Guianas: Pyrenula cubica Sipman, with cubical central lumina in the ascospores; Pyr­enula flavida Sipman, with a yellow-pigmented thallus; P. rubromarginata Sipman, with red pigment on the excipulum and not on the thallus; and P. submicromma Sipman, like P. micromma but with submuriform instead of bacillar ascospores. In addition, a description for P. atropurpurea is provided, and P. subvariabilis is reduced to synonymy of P. infrastroidea. Special attention was paid to the development of the ascospores. Two different development types are recognized. The phylogenetic significance of these types is unclear.