Cunningham (1965: 90) provided a good description of the species and transferred it to Grifola S.F. Gray because fruit-bodies usually consist of a cluster of imbricate pilei joined by a tuberous base. G. frondosa (Fr.) S.F. Gray, the type species, is similar to G. rosularis in having the same type of hyphal system and spores, although both spores and pores of G. frondosa are larger.
G. rosularis could be considered to belong in Tyromyces, which includes many species with imbricate basidiocarps, a monomitic hyphal system, and subglobose to ellipsoid, nonamyloid, nondextrinoid spores; T. pubescens (Fr.) Pilat is a representative example of this group. However, almost all Tyromyces species produce applanate basidiocarps on dead wood rather than semistipitate basidiocarps arising from a common base. Thus we maintain the species in Grifola.

Holotype: PDD 3914 - New Zealand, Gisborne, Lake Waikaremoana, Waikareiti Track, Jan. 1933, J.G. Gibbs, on Nothofagus sp.