NOTES: Peristomialis cellularis is characterised by solitary, lightly pigmented, more or less globose ascomata, which have simple or branched appendages composed of irregularly intertwined hyphae. Based on the morphology of the ascomatal wall and appendage tissues this species is best treated as a member of Peristomialis, close to P. parilis (H. Sydow) Samuels and P. paraparilis Samuels (Samuels, 1988a). In P. paraparilis and P. parilis the ascomata are similar to P. cellularis in being made of intertwined hyphae and having appendages also composed of intertwined hyphae. However, in P. paraparilis the asci are 63–80 × 12.5–18 µm and the ascospores are 1-septate, coarsely striate and 19.5–25.5 × 4–5 µm. Peristomialis parilis differs in having a narrow ostiolar opening and well developed, longer, fasciculate appendages, which are typically produced around the ostiolar region but can be scattered irregularly over the entire perithecial surface. These appendages can also be irregularly branched. The appendages of P. parilis are described as “short, fasciculate, triangular hairs or wart-like processes” and are produced around the ostiolar disc (Samuels, 1988a). As the asci and ascospores of P. parilis are very similar to the current specimens these two taxa may prove to be conspecific, but based on the narrow ostiolar opening, the well developed fasciculate appendages and their development over the entire perithecial surface, P. cellularis is introduced as new.

MATERIAL EXAMINED: NEW ZEALAND, North Island, Auckland Region, Hunua Ranges, Workman Track, on decaying leaves of Freycinetia banksii, 8 May 1996, S.R. Whitton HKU(M)12701 (IFRD8992, holotype); North Island, Kapiti Coast, north of Paraparaumu, Nikau Reserve, on decaying leaves of F. banksii, 2 June 1996, S.R. Whitton HKU(M)5069 (IFRD212-005); North Island, Kapiti Coast, north of Paraparaumu, Nikau Reserve, on decaying leaves of F. banksii, 1 May 1997, S.R. Whitton HKU(M)5061 (IFRD210-025); HKU(M)5062 (IFRD210-025);; North Island, Wellington Region, Wainuiomata Valley, in the forest surrounding Wainuiomata Reservoir, on decaying leaves of F. banksii, 6 May 1997, S.R. Whitton HKU(M)12885 (IFRD220-005).