Tomentella africana, a new species from Benin (West Africa) identified by morphological and molecular data

Abstract

A common resupinate thelephoroid fungus was collected in northern Guinean seasonal forests in central and north of Benin (West Africa). The species is reminiscent of Tomentella umbrinospora with respect to the color and thickness of basidiomata and rhizomorphs, the shape of basidiospores in frontal view and the size of subicular hyphae. Both species fall phylogenetically within two clades. Based on detailed anatomical comparison (mostly of rhizomorphs and basidiospores) with the holotype of T. umbrinospora and phylogenetic analyses including ITS rDNA sequences of 40 Tomentella species, T. africana is described as a new species. Genetic distance between the newly described species and T. umbrinospora is 12.1–12.9%, based on ITS rDNA sequences. T. africana is characterized anatomically by yellow-brown thick (0.3–0.8 mm) monomitic rhizomorphs that are commonly covered by irregularly shaped thin hyphae, thin- to thick-walled subicular hyphae of two size ranges, clavate and clamped basidia of 30–60 μm and light yellow to pale brown echinulate basidiospores with irregular shape in frontal view. Detailed anatomical and molecular dissimilarities between T. africana and close species are discussed. Differences between irregularly shaped surface thin hyphae and skeletal ones are highlighted. We stress the relevance of rhizomorphal structures in the discrimination of resupinate thelephoroid fungi.

• anatomy
• hyphal system
• ITS rDNA sequences-based phylogeny
• rhizomorphal structure
• T. Africana
• T. umbrinospora
• tropical Africa

We are much indebted to the German Academic Exchange Service (DAAD) for financial support (grant No. A/03/15106). The African Forests Research Network (AFORNET) through grant No. 02/2005 and the International Foundation for Science-IFS-(grant D/4033-1) jointly financed the collection trips and equipments. We also thank Dr Scott Kroken (associate editor) and Dr Clovis Douanla-Meli (University of Kassel, Germany) for their valuable advice with molecular studies. Drs Eva Facher and Thassilo Franke are much thanked for their technical help with SEM.