Three new Tomentella species from West Africa identified by anatomical and molecular data

Abstract

We used a combination of molecular-phylogenetic inference of 82 ITS rDNA sequences and anatomical approach to describe three new west African thelephoroid species, namely Tomentella afrostuposa, T. guineensis and T. guinkoi. Anatomically, T. afrostuposa is reminiscent of T. stuposa with globose to broadly ellipsoid large basidiospores of 8–14 μm, long aculei of up to 3 μm and prominent apiculi of 2 μm width. Molecular-phylogenetically, it falls within the T. stuposa complex. However, T. afrostuposa deviates by at least 7.80–10.74% from T. stuposa in regard with the ITS rDNA sequences. Tomentella guineensis is characterised by long (up to 85 μm) utriform basidia, the presence of reniform basidiospores in lateral view (up to 9 μm) with aculei not exceeding 1 μm and a strong cyanescent reaction of the subhymenial hyphae and basidia in 2.5% KOH. It forms a sister species of the newly described species Tomentella maroana; however, deviating from the last species by at least 9.75–10.04%. The very short, inflated (up to 14 μm) and thick-walled septate (septa up to 1.5 μm) subhymenial hyphae combined with ellipsoid basidiospores (up to 8 μm) and short aculei not exceeding 0.5 μm characterise Tomentella guinkoi. Anatomically, T. guinkoi recalls T. ellisii. Genetic distance between both species ranges from 12.67 to 13.73% according to ITS rDNA sequences analyses. Tomentella guinkoi forms a sister species of the group composed of T. ellisii, T. hjortstamiana and T. pisoniae. Detailed anatomical comparisons between the newly described species and their close relatives are given.