Two species of the genus Hypoxylon Bull. ex Fr. em. J. H. Miller (section Hypoxylon) are reported, found on branches of Fraxinus angustifolia Vahl in South Moravian bottomland forests: Hypoxylon fraxinophilum Pouz. spec. nov., previously known under the illegitimate name (later homonym) Hypoxylon argillaceum (Pers. ex Pollini) Nitschke, and Hypoxylon moravicum Pouz. spec. nov., a species similar to H. rubiginosum (Pers. ex Fr.) Fr., differing in the peculiar development of stromata (stellate in young stages) and the inamyloid apical apparatus of asci.
Pouzar Z. (1972): Hypoxylon fraxinophilum spec. nov. and H. moravicum spec. nov., two interesting species found on Fraxinus angustifolia. – Česká Mykologie 26(3): 129–137.