Pesotum accommodates synnematal anamorphs of Ophiostoma spp. with sympodially proliferating conidiogenous cells. These fungi are usually closely associated with wounds on trees and the insects that visit them. During tree disease surveys in Uganda, as well as studies of fungi infecting wounds on Acacia mearnsii trees in Uganda and Australia, many isolates resembling species of Pesotum were collected. The aim of this study was to identify these fungi using both morphological and DNA sequence comparisons. The Pesotum, anamorph of O. quercus was the only species collected from multiple collections in Uganda. Collections from Australia represent a new species of Pesotum described here as P. australi sp. nov.