Specimens studied. NEW ZEALAND. Auckland: Piha, Glen Esk Valley, 300 m, on Neopanax arboreum, V-1951, PDD 11240 (holotype, PDD); on Letptospermum scoparium, J.M. Dingley, III-1956, PDD 17037 (PDD). Cascade Kauri Park, Waitakere Ranges, 300 m, on Brachyglottis repanda, III-1950, PDD 7911 (PDD); Waitakere Ranges, Anawhata Rd, on N. arboreum, J.M. Dingley, V-1954, PDD 15463 (PDD).

Descriptions and line drawings of this species were provided by Cunningham (1963) and Stalpers (1985). Stalpers (1985) considered Corticium crystallitectum to be conspecific with Boidinia peroxydata, but we find that the two species can be distinguished by basidiospore size. Basidiospores of C. crystallitectum have been described as 5-6.5 x 3.5-4.5 µm (Cunningham, 1963) and (4.5-)5-5.5 x 3.5-4.2 µm (Stalpers, 1985). Our measurements of basidiospores from 4 collections (PDD 7911, 11240-holotype, 15463, 17037) are (5.5-)6-7(-8) x 3.5-5 µm. These measurements are distinctly larger than those of basidiospores from the holotype of B. peroxydata (3.8-4.8 x 2.9-3.3 µm) measured in this study.
While examining Cunningham's collections labelled Corticium crystallitectum in Herb. PDD, we found that specimens on Cyathea (Filicales) represent a discordant element; specimens PDD 7895 and 17106 have clavate basidia and shorter spores than those of B. crystallitecta and appear to belong in Gloeocystidiellum s.s.