Pi1eus 3-5 mm diam, hemispherical to convex with a central, low, obtuse papilla (often only wart-like), weakly plicate; surface dull, dry, minutely pruinose; off white to pale grey, turning pale reddish brown with KOH; dried pilei appearing like plastic. Texture membranaceous; context very thin, white.-Lamellae adnexed, distant (7-9) with no lamellulae or with a few scattered lamellulae, subventricose, off-white; edges fimbriate, concolorous.- Stipe 12-28 x 0.3-0.5 mm, central, equal, cylindrical, wiry, tough, conspicuously pruinose overall, insititious; apex white, black elsewhere. Odor and taste not distinctive.
Basidiospores 8-11 x 4-5 µm, broadly subfusoid, smooth, thin-walled, hyaline, inamyloid.- Basidia 30-36 x 6-7 µm, subclavate to subcylindrical, 4-spored, clamped.- Cheilogloeocystidia abundant, 45-70 x 6-11 µm, tibiiform, capitulum 7-10 µm diam., thin-walled, hyaline, with reddish brown plasmatic pigment in KOH.- Pleurogloeocystidia absent. - Pileipellis a hymeniform layer of subcylindrical to clavate cells, 20-60 x 4-12 µm, thin-walled, hyaline, with orange resinous contents; capitate pileo-gloeocystidia absent.- Tissues inamyloid, non-gelatinous.- Caulocystidia of 2 types: a) caulogloeocystidia 30-70 x 8-10 µm, tibiiform to fusoid-capitate, thin-walled to thick-walled, capitulum 5-7 µm diam.; walls hyaline, with brown plasmatic pigment; b) scattered caulosetae, 50-60 x 8-10 µm, fusoid to lanceolate, acute, thick-walled (up to 1 µm diam); walls hyaline at stipe apex, brown elsewhere.- Clamp connections present.

Habit, habitat and distribution.- Solitary, on rotting twigs of Nothofagus fusca (Fagaceae), not on leaves. New Zealand.

Pileus 3-5 mm, hemisphaericus vel convexus, papilla obtusa centraliter instructus, subplicatus, minute pruinosus, subalbus vel pallide griseus. Lamellae adnexae, distantes, subalbidae. Stipes 12-28 x 0.3-0.5 mm, centralis, cylindricus, conspicue pruinosus, insiticius, apicaliter albus sursum niger. Odor saporque nulli. Basidiosporae 8-11 x 4-5 µm, late subfusoideae, leves, hylinae, inamyloideae. Basidia 30-36 x 6-7 µm, 4-spora. Cheilogloeocystidia 45-70 x 6-11 µm, tibiiformia, capitulo 7-10 µm diam. instructa, tenuitunicata, pigmento rubrobrunneo impleta. Pleurogloeocystidia nulla. Pileipellis hymeniformis, ex cellulis subcylindraceis clavatisque, 20-60 x 4-12 µm, tenuitunicatis, hyalinis, pigmento aurantiaco resinaceo instructis. Pileogloeocystidia capitata desunt. Trama inamyloideum, haud gelatinosum. Caulocystidia: a) 30-70 x 8-10 µm, tibiiformia vel fusoideocapitata, capitulo 5-7 µm diam., membrana hyalina et pigmento brunneo plasmatico instructa; b) 50-60 x 8-10 µm, cauloseta affines, fusoidea vel lanceolata, acuta, crassetunicata. Fibulae praesentes. Solitarius, ad ramos putridos Nothofagi fuscae. Nova Zelandia. Horak 67-254 (Holotypus, PDD).

Gloiocephala nothofagi displays a number of unusual features, including a pileipellis composed of subcylindrical gloeocystidioid cells of varying lengths but lacking projecting capitate gloeocystidia, and caulocystidia of two types, viz. capitate gloeocystidia like those in the hymenium, plus setae. This combination of characters is unique in Gloiocephala. The pigmented pileus would suggest placement in sect. Gloiocephala, subsect. Religiosae.
Macroscopically, G. nothofagi is reminescent of G. caucasica (Sing.) Singer, but the latter species differs in forming thick-walled, broadly clavate to sphaeropedunculate pileipellis cells, and ventricose-mucronate hymenial cystidia (fide Singer, 1937).

Material examined- - NEW ZEALAND: South Island, Prov. Westland, Ahaura, Kopara, 15 XII 1967, Horak 67-254 (Holotype, PDD; Isotype, SFSU, ZT).