All specimens for descriptions were cultivated from the same field-collected stock culture (Table 1, CHU3002: Suzuki et al. 2002), isolated from urea-treated plots in Nothofagus forest, Taupo, New Zealand: PDD 76873—Holotype; FB-30231, FB-30236, FB-30238, FB-30240 (CBM); FB-24558 (spore print, CBM). Specimens produced from other stock cultures from Taupo: FB-24562, 24568 (CBM); from Riverhead, New Zealand: FB-24554 (CBM); from Dwellingup, Australia: FB-24556 (CBM). Field collected materials were also examined; from Dwellingup, Australia, PERTH 07598351 and PERTH 07599137

Pileus 5–10 mm broad, 6–12 mm high in button stage, when young ellipsoid to ovoid, later convex to plane, 15–20 mm broad when expanded, radially sulcate, at length the edge somewhat recurving and splitting irregularly, pileipellis color at first white, soon becoming brown (6d6), surface when young densely covered with white, radially arranged, hairy-fibrillose scales (Figs. 1, 2) or squarrose recurved scales (Figs. 4, 5), sometimes with cortinate veil in very young stage (Fig. 4), later almost glabrous or veil remaining only in the center (Fig. 6). Flesh very thin, fragile, white, taste mild, odorless. Lamellae free, crowded (number of lamellae reaching stipe = 70–85), narrow (1–2 mm wide), edge slightly pruinose, at first white, then grayish, finally blackish, deliquescent. Stipe up to 50–100 mm 9 1–3 mm, cylindrical, equal or somewhat tapering upward, sometimes the base clavate, not rooting, hollow, fragile, surface white, at first with white fibrillose or squarrose scales (Figs. 3, 4, 5), soon becoming smooth (Fig. 6). Basidiospores black in mass, dark red-brown under the microscope, ovoid to ellipsoid, 6.5–7.5 (7.0 ± 0.3: mean ± SD, n = 40) lm long, 5.1–6.5 (5.7 ± 0.4, n = 20) lm broad in face view, 5.1–6.2 (5.6 ± 0.3, n = 20) lm in side view (dimensions including ornamentation); 6.2–6.8 (6.6 ± 0.3, n = 40) lm long, 4.9–6.0 (5.4 ± 0.3, n = 20) lm broad in face view, 4.8–5.6 (5.3 ± 0.2, n = 20) lm in side view (dimensions without ornamentation), with warty ornamentation, an apical, central germ pore 0.7–0.8 lm wide and a clear plage (Figs. 7a, 8, 9). Basidia 14–25 9 6–7.5 (long type: 20–25 9 6–7.5, short type: 14–18 9 6–7) lm, 4-spored (Fig. 7b). Pleurocystidia 65–80 9 40–50 lm, subellipsoid to obovoid, thin-walled, hyaline, scattered and projecting from the hymenium (Fig. 7c). Cheilocystidia 35–50 925–30 lm, subellipsoid to obovoid, thin-walled, hyaline, numerous, but not forming sterile margin (Fig. 7d). Veil on the pileal surface composed of thin-walled, diverticulate, hyaline hyphae, 50–150 9 4–6 lm (Fig. 7e). Clamp connections present on veil hyphae (Fig. 7e), on pleuro- and cheilocystidia hyphae (Fig. 7c, d) and on pileal trama hyphae.

MycoBank no.: MB 518948 Pileo primo 5–10 mm lato 6–12 mm alto, usque ad 15–20 mm lato, ovato-campanulato, demum in margine lacerato revolutoque, radiatim sulcato, candido vel eburneo, deinde cinerascenti, primo squamis albis radiatim hirsuto fibrillosis squarrosis interdum recurvis ubique tecto, dein fere glabro, interdum primo cortinato; carne tenuissima, fragilissima, alba; sapore miti; odore nullo; lamellis liberis, comfertis, angustis (1–2 mm), albis, deinde atratis, deliquescentibus; stipite 50–100 mm longo, 1–3 mm crasso, aequali vel sursum leviter attenuato, basi leviter incrassatulo, cavo, candido, fragilissimo, primo squamis albis fibrillosis squarrosis ubique tecto, dein glabro; basidiosporis in cumulo atratis, sub microscopio atro-brunneis vel rufobrunneis, ovoideis vel ellipsoideis, 6.5–7.5 9 5.1–6.5 (frontali) 9 5.1–6.2 (laterali) lm, verrucosis, poro germinationis centrali 0.7–0.8 lm lato, cum plagiis; basidiis 14–25 9 6–7.5 lm, tetrasporis; pleurocystidiis 65–80 940–50 lm, subellipsoideis vel obovatis, hyalinis, tenuitunicatis; cheilocystidiis 35–50 9 25–30 lm, subellipsoideis vel obovatis, hyalinis, tenuitunicatis; velo pilei ex hyphis tenuitunicatis, divaricatis, hyalinis, 50–150 9 4–6 lm composito; fibulis praesentibus. Holotypus: New Zealand, leg. T. Fukiharu, in Herbario Fungorum Novae Zelandiae conservatus (PDD 76873).