This species is closely related to Cylindrobasidium albulum (G.F.Atk. & Burt) J. Erikss. & Hjortstam and C. torrendii (Bres.) Hjortstam, preferably by its morphology of spores and cystidia. The former are typically pip-shaped and often in pairs or 3-4. C. coprosmae seems to be rather well separated from both, above all by a very dense hyphal texture and basidial layer. There is a good original description and Cunningham also pointed out the similarity with Corticium evolvens Fr.:Fr. [=Cylindrobasidium evolvens (Fr.:Fr.) Jülich]. It should be noted that Stalpers (1985) transferred C. coprosmae to Chondrostereum Pouzar. The latter is a pileate (or sometimes resupinate) genus with differently shaped spores and is reminiscent of Phlebia Fr. (see Eriksson and Ryvarden 1973). Chamuris (1988) did not accept C. coprosmae in Chondrostereum.

Isotype: New Zealand, Auckland, 1946, J. M. Dingley, PDD 4528 (K).