Acanthothecis sarcographoides (Ascomycota: Graphidaceae), a morphologically unique, new lichen species in the Atlantic Forest of northeastern Brazil

Marcela Eugenia Da Silva Cáceres,Robert Lücking

doi:10.1590/s0102-33062013000300002

Marcela Eugenia Da Silva Cáceres, Robert Lücking

Open Access

https://doi.org/10.1590/s0102-33062013000300002

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Abstract

A new species of Acanthothecis is described in the Atlantic Forest of northeastern Brazil. Unlike any other species in the genus, it has distinctly pseudo-stromatic ascomata that resemble those of the genus Sarcographa. However, its apically spinulose paraphyses, I-negative ascospores with thin endospore closely resemble those of other Acanthothecis species. A previous molecular phylogenetic analysis places the new species close to the type species of Acanthothecis, A. hololeucoides. The discovery of this unique new species underscores the importance of thorough biotic surveys in the Atlantic Forest of Brazil, where it is likely that many more unknown lichen species await discovery.

Highlights

The family contained only species with lirellate ascomata, which were divided into eight genera depending on ascospore septation/color and ascomata organization (Wirth & Hale 1963, 1978; Staiger 2002)
Species of Acanthothecis are recognized by whitish, lirellate ascomata, mostly without exciple carbonization, hymenium comprising paraphyses with finely spinulose apices, and ascospores with poorly developed endospores that do not react to iodine solution (Staiger & Kalb 1999; Staiger 2002; Lücking & Rivas-Plata 2008)
We describe a unique new species of Acanthothecis, similar to other species in the genus in terms of its hymenial and ascospore characters but differing in that it has distinctly pseudo-stromatic ascomata, resembling those of the unrelated genus Sarcographa, being the first Acanthothecis species known to have this characteristic

Summary

Introduction

Graphidaceae is the largest family of tropical lichens, comprising nearly 2000 species world-wide (Staiger 2002; Frisch et al 2006; Archer 2006, 2007, 2009; Lücking & Rivas Plata 2008; Lücking 2009, 2012; Lücking et al 2008, 2009; Rivas Plata et al 2012, 2013; Mangold et al 2009; Rivas Plata & Lücking 2012; Sipman et al 2012). It is the dominant element of lichen communities in tropical rain forests (Cáceres et al 2007, 2008; Lücking et al 2008; Rivas Plata et al 2008).

Results

Conclusion