Based on the discussion in Spooner (1987), Asterocalyx had frequently been placed close to Godronia (e.g. Hohnel 1912, 1918; Clements & Shear 1931; Nannfeldt 1932; Korf 1973), the genera sharing gelatinised excipulum and elongated ascospores. Dumont & Carpenter (Mycologia 70: 68-75, 1980) placed the genus in the Sclerotiniaceae because the host tissue beneath the apothecia was blackened. It is now known that blackened host tissue is not a useful character for higher level taxonomy in the Leotiomycetes. DNA sequences from recent New Zealand and Australian specimens of Asterocalyx agree with the older litertaure, placing the genus close to Godronia and Gremenniella, both of these genera belonging in the Godroniaceae sensu Baral 2015.
The Australian and New Zealand specimens sequenced have distinct ITS sequences (95% identical), and these two different species differ also in ascus and ascospore size and somewhat in macroscopic appearance. Spooner (1987) noted that the Australian specimen he examined was morphologically somewhat different to the type specimen from Java. The PDD specimen from the Solomon Islands is macroscopically quite distinct. There appear to be a set of closely related, undescribed Asterocalyx species on ferns in Australasia and tropical Asia. For now, the PDD specimens are all accepted as A. mirabilis.