Species of the genus Hermatomyces (Hermatomycetaceae, Pleosporales) are saprotrophic anamorphic ascomycetes that have been intensively studied mostly in South-East Asia and Panama. Species concepts were recently revised based on specimens from these regions using both phenotypic and molecular data.
However, other tropical areas have been mostly overlooked, e.g. Africa, although members of the genus were collected from this continent in the past.
Therefore, specimens available at the fungarium of Kew were studied. Most of them originated from western Africa, specifically Ghana and Sierra Leone, but collections from Ethiopia, India, and Malaysia were also revised.
Among them, a new species was found and is described and illustrated herein as H. truncatus. The fungus colonized dead branches of Averrhoa carambola in Ghana and is characterized by two types of conidia; the cylindrical ones are 2-, rarely 3-celled, with a central or eccentric septum and the upper cells rounded but slightly flattened at the apex, often distinctly widening and dark brown or black in color.
An additional collection of this fungus from Panama was also studied. Recently collected specimens from Puerto Rico and Australia are included and the known distribution of the following species is updated with new regions: H. indicus (first record from Sierra Leone), H. megasporus (Ethiopia), H. reticulatus (Ethiopia) and H. sphaericus (Puerto Rico and Australia).