Renewed study of the type material of species formerly described under Xylaria necessitates the recognition of a new family, for which the name Sarcostromellaceae Boedijn is proposed. This family comprises two new genera, Sarcostromella Boedijn and Pseudoxylaria Boedijn. Sarcostromella polysticha (Penz. & Sacc.) Boedijn and Pseudoxylaria nigripes (Kl.) Boedijn are new combinations, S. amorpha Boedijn is a new species. Xylaria xanthophaea Penz. & Sacc. appears identical with S. polysticha. Xylaria torrubioides Penz. & Sacc. is a synonym of Pseudoxylaria nigripes.