Macrolichens are considered to be well known, including the tropical montane basidiolichen fungus Dictyonema glabratum, also known as Cora pavonia, an important component of threatened paramo ecosystems, where it acts as a biological fertilizer due to its ability to fix atmospheric nitrogen. This lichen was long believed to represent a single species, but after revising this number to 16 in two genera (Cora and Corella), here we show that at least 126 phylogenetically and morphologically distinct species are contained within this group, with statistical analysis predicting more than 400. Our findings underline the importance of accurately documenting species richness for conservation purposes and support the notion of neotropical paramos as hotspots of recent diversification in plants, animals, and fungi.

Abstract

The number of Fungi is estimated at between 1.5 and 3 million. Lichenized species are thought to make up a comparatively small portion of this figure, with unrecognized species richness hidden among little-studied, tropical microlichens. Recent findings, however, suggest that some macrolichens contain a large number of unrecognized taxa, increasing known species richness by an order of magnitude or more. Here we report the existence of at least 126 species in what until recently was believed to be a single taxon: the basidiolichen fungus Dictyonema glabratum, also known as Cora pavonia. Notably, these species are not cryptic but morphologically distinct. A predictive model suggests an even larger number, with more than 400 species. These results call into question species concepts in presumably well-known macrolichens and demonstrate the need for accurately documenting such species richness, given the importance of these lichens in endangered ecosystems such as paramos and the alarming potential for species losses throughout the tropics.