Specimen examined. New Zealand • South Island, Westland District, Granville Forest, Orwell Creek, on leaves of Nothofagus fusca., 2 Apr 1963, S.J. Hughes, from mixed collection, DAOM 106914 (C. atro-olivaceus isotype).
Notes. The mature hyphae of M. australis and Capnobotrys atro-olivaceus that are intermingled mycelia in the subiculum of DAOM 106914 differ in diameter and color. Hyphae of M. australis are up to 29 µm wide and are brown without olivaceous tints, while mature hyphae of C. atro-olivaceus are up to 16.2 µm wide and are “dull, dark olivaceous brown” (Hughes 1981).
In the ITS phylogeny, M. australis appears as sister to M. dingleyae (Fig. 2). Hughes (1981) distinguishes M. australis from three similar species: Capnobotrys laterivecta, C. paucisporus, and M. dingleyae that share a capnobotrys form and curved hyphae with upwardly curving or straight branches that arise at right angles, and more or less doliiform component cells. Most similar to M. australis is C. laterivecta, which can be distinguished from M. australis by its larger conidia and by the unusual attachment of its conidia by their long sides, just below their septa, to conidiogenous cells (Hughes 1981). Metacapnodium australis has smaller conidia and a larger number of conidiogenous cells at hyphal tips compared to C. paucisporus. Metacapnodium dingleyae can be easily distinguished by the presence of conidia with more than one septum (Hughes 1981). The prominent constrictions at the septa and coarse warts on capnobotrys conidia of M. australis help distinguish this species from others with capnobotrys forms, including M. moniliforme.