Asterosporium Kunze, Flora, Regensburg 2: 225 (1819)
Diaporthomycetidae, Diaporthales, Asterosporiaceae, Asterosporium
Endophytic, saprobic or pathogenic on Betulaceae, Fagaceae, Juglandaceae and Sapindaceae. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata acervular, subepidermal, erumpent at maturity, solitary, or occasionally confluent, unilocular, dark brown to black. Conidiomata wall composed of thin-walled, brown cells of textura angularis. Conidiophores cylindrical, branched at the base, septate, hyaline to pale brown. Conidiogenous cells holoblastic, cylindrical, unbranched, integrated, determinate, hyaline to pale brown, smooth. Conidia terminal, transversely distoseptate, consisting of four arms, with reduced lumina, brown, smooth-walled (adapted from Senanayake et al. 2017).
Type species: Asterosporium asterospermum (Pers) S. Hughes, Can. J. Bot. 36: 738 (1958)
Notes: Asterosporium was introduced and typified by A. hoffmannii. Hughes (1958), however, regarded Stilbospora asterosperma as the older name for this taxon based on morphology. Hence, a new combination, Asterosporium asterospermum was proposed. However, according to molecular analysis conducted by Hyde et al. (2020), A. asterospermum and A. hoffmannii are phylogenetically identical. Hence, A. hoffmannii (1819) has been synonymized under A. asterospermum (1801), with priority given to the older name. While most species of Asterosporium are saprobic on decaying wood, A. hoffmannii may cause cankers and branch dieback of beech (Pirone 1978). Asterosporium asterospermum has been reported to cause canker on Fagus crenata and F. sylvatica as a mild pathogen (Sieber 2007).
Hughes SJ. 1958 – Revisiones hyphomycetum aliquot cum appendice de nominibus rejiciendis. Canadian Journal of Botany 36, 726–836.
Hyde KD, Norphanphoun C, Maharachchikumbura SSN, Bhat DJ et al. 2020 – Refined families of Sordariomycetes. Mycosphere 11, 305–1059.
Pirone PP. 1978 – Diseases and Pests of Ornamental Plants. Wiley-interscience Publication.
Senanayake IC, Crous P, Groenewald J, Maharachchikumbura SSN et al. 2017 – Families of Diaporthales based on morphological and phylogenetic evidence. Studies in Mycology 86, 217–296.
Sieber TN. 2007 – Endophytic fungi in forest trees: are they mutualists? Fungal Biology Reviews 21, 75–89.