Abstract
Longipedicellata gen. nov. is introduced to accommodate the common freshwater ascomycete Didymella aptrootii which occurs on bamboo in freshwater. It is characterized by lenticular ascomata, immersed beneath a blackened pseudoclypeus, with relatively large ostioles, sparse pseudoparaphyses, bitunicate, broadly clavate asci, with a long pedicel and 1-septate, hyaline ascospores, surrounded by large irregular mucilaginous sheath. Illustrated accounts of the type and fresh collections of Longipedicellata aptrootii are provided and morphological differences between Longipedicellata and some related taxa are noted. We place Longipedicellata in Bambusicolaceae, based on analysis of LSU, SSU, RPB2 and TEF sequence comparisons.