Hymenochaetaceae from the Guineo-Congolian Rainforest: Phylloporia flabelliforma sp. nov. and Phylloporia gabonensis sp. nov., Two Undescribed Species from Gabon
Phylloporia flabelliforma sp. nov. and Phylloporia gabonensis sp. nov. are described on the basis of specimens originating from the western edge of the lower Guineo- Congolian rainforest, in Gabon. Both species form seasonal, gregarious and sessile basidiomata, with spathulate to flabelliform pilei, emerging in dense clusters at the lower part of living trunks of Dichostemma glaucescens and Anthostema aubryanum, two small-stemmed Euphorbiaceae from the understorey compartment. Both taxa have a pileus surface in a grayish orange tone when fresh, 5–6 irregular pores/mm and a homogeneous, pale cork-colored context, briefly discoloring to reddish or reddish brown in 3% alkali. The hyphal system is monomitic and the basidiospores are ellipsoid to broadly ellipsoid in both species. Phylloporia flabelliforma is specifically characterized by thin pilei, ≤ 1.5 mm at the thickest, with a shiny surface and a thin, and regular white margin. Phylloporia gabonensis has thicker pilei with a dull surface and a lobed, incised margin. Phylogenetic inferences using DNA sequence data from partial nuc 28S (region including the D1/D2/D3 domains) resolved these two species as two distinct but closely related sister clades within the Phylloporia lineage. Phylogenetic inferences using DNA sequence data from the ITS regions confirmed the results obtained from the nuc 28S. These two species are compared to P. fulva and P. inonotoides, both occurring in the same phytochorion in Gabon. They are also compared to Inonotus pusillus and I. dentatus, two species known only from the Neotropics.