Twenty-one new species of Pyrenula from South America, with a note on over-mature ascospores

Twenty-three species of Pyrenula from Latin America are treated here. Several species show characters that were not previously reported in the genus and are rare or new to lichenized fungi, viz. yellow, orange or red (KOH+ green) oil inspersion in the hymenium, yellow oil in young ascospores or longitudinal ridges on the ascospore wall. Two taxonomically significant types of over-mature spores are illustrated. The following new species are described: Pyrenula aggregataspistea Aptroot & M. Caceres, P. aurantioinspersa Aptroot & Sipman, P. cornutispora Aptroot & M. Caceres, P. flavoinspersa Aptroot & Sipman, P. guyanensis Sipman & Aptroot, P. infraleucotrypa Aptroot & M. Caceres, P. inframamillana Aptroot & M. Caceres, P. infrastroidea Aptroot & Sipman, P. maritima Sipman & Aptroot, P. mattickiana Sipman & Aptroot, P. minoides Aptroot & Sipman, P. monospora Aptroot & Sipman, P. paraminarum Aptroot & M. Caceres, P. perfecta Aptroot & Sipman, P. plicata Sipman & Aptroot, P. rubroinspersa Aptroot & Sipman, P. rubronitidula Aptroot & M. Caceres, P. rubrostigma Aptroot & M. Caceres, P. tetraspora Aptroot & Sipman, P. triangularis Aptroot & Sipman, P. viridipyrgilla Aptroot & M. Caceres. Pyrenula seminuda (Mull. Arg.) Sipman & Aptroot is a new combination.