Rostania revised: testing generic delimitations in Collemataceae (Peltigerales, Lecanoromycetes).

Alica Košuthová,Mats Wedin,Martin Westberg,Mónica A.G Otálora

doi:10.3897/mycokeys.47.32227

Alica Košuthová, Mats Wedin + Show 2 more

Open Access

https://doi.org/10.3897/mycokeys.47.32227

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Abstract

Here, we test the current generic delimitation of Rostania (Collemataceae, Peltigerales, Ascomycota) utilizing molecular phylogeny and morphological investigations. Using DNA sequence data from the mitochondrial SSU rDNA and two nuclear protein-coding genes (MCM7 and β-tubulin) and utilizing parsimony, maximum likelihood and Bayesian phylogenetic methods, Rostania is shown to be non-monophyletic in the current sense. A new generic delimitation of Rostania is thus proposed, in which the genus is monophyletic, and three species (Rostaniacoccophylla, R.paramensis, R.quadrifida) are excluded and transferred to other genera. Rostaniaoccultata is further non-monophyletic, and a more detailed investigation of species delimitations in Rostania s. str. is needed. The new combinations Leptogiumparamense and Scytiniumquadrifidum are proposed.

Highlights

Collemataceae is a large group of predominantly foliose lichenized fungi commonly known as the “jelly lichens” due to their gelatinous habit
All Rostania species are nested within Collemataceae, but Rostania in the sense of Otálora et al (2013b) is non-monophyletic
Three species form a core group, which we here treat as Rostania s. str

Summary

Introduction

Collemataceae is a large group of predominantly foliose lichenized fungi commonly known as the “jelly lichens” due to their gelatinous habit. This is caused by a polysaccharide matrix around the Nostoc cyanobacterial photobionts that swells and becomes extremely gelatinous when wet. Already Degelius (1954) questioned the monophyly of Collema and Leptogium This was supported by molecular phylogenies (Wiklund and Wedin 2003; Miadlikowska and Lutzoni 2004; Miadlikowska et al 2014), and somewhat surprisingly, gelatinous genera with one-septate spores that earlier were classified in Collemataceae, were shown to belong to the Pannariaceae (Wedin et al 2009; Otálora et al 2010; Ekman et al 2014; Weerakoon et al 2018) or Arctomiaceae (Otálora and Wedin 2013). Arg., Rostania Trevis., and Scytinium (Ach.) Gray), and two new genera were described (Callome Otálora & Wedin and Paracollema Otálora & Wedin)

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