Sclerotrema Spirin & Malysheva, in Fungal Biology 121(8): 712 (2017)
Etymology: ‘skleros’ (Greek, adj.) – dry, and ‘trema’ – a reference to tremellaceous fungi, an artificial group encompassed many heterobasidiomycetes.
Diagnosis: Basidiocarps perennial, orbicular, often fusing together. Hymenophore smooth, greyish brown. Hyphal structure monomitic, hyphae clamped, sometimes irregularly inflated, hyaline. Cystidia present. Basidia ellipsoid-ovoid to subglobose, longitudinally septate, constantly four-celled, embedded. Basidiospores hyaline, allantoid, distinctly curved, with oily inclusions. On dry branches and logs of deciduous trees.
Index Fungorum number: IF818036
Type species: Sclerotrema griseobrunneum (K. Wells & Raitv.) Spirin & Malysheva, in Fungal Biology 121 (8): 696 (2017)
Notes: The genus was described to accommodate one species, formerly addressed to the genus Exidiopsis. In the protologue, Raitviir & Wells (1966) pointed to the similarity of E. griseobrunnea and E. alliciens; however, DNA data do not support their close relationships. Exidiopsis spp. (E. effusa, E. grisea etc.) differ from Sclerotrema in having annual (except E. calcea) and light–coloured basidiocarps, gelatinized at least at earlier stages of their development.
Figure 1. Combined phylogenetic nrITS D nrLSU topology from Maximum likelihood analysis showing main lineages within Auriculariales. The collection number (voucher or isolate) is given for each specimen. Support values (PP values in BI/BS values in ML/BS values in MP) are given above the branches. Scale bar shows expected changes per site.
Raitviir A, Wells K. (1966) Two new species of Exidiopsis. Eesti NSV Teaduste Akadeemia Toimetised 15: 206–209