Studies in Hygrocybe s. l. (Hygrocyboideae, Hygrophoraceae) in Brazil: New species of Humidicutis and Neohygrocybe Author Cardoso, Juli Simon 0000-0003-2795-7067 Divisão do Curso de Pós-graduação em Botânica, Instituto Nacional de Pesquisas da Amazônia (INPA), Av. André Araújo 2936, 69067 - 375, Manaus, AM, Brazil & jul 3 asc @ gmail. com; https: // orcid. org / 0000 - 0003 - 2795 - 7067 jul3asc@gmail.com Author Moncalvo, Jean-Marc 0000-0003-4011-1381 Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON M 5 S 3 B 2, Canada & Department of Natural History, Royal Ontario Museum, 100 Queens Park, Toronto, ON M 5 S 2 C 6, Canada & jeanmarcm @ gmail. com; https: // orcid. org / 0000 - 0003 - 4011 - 1381 jeanmarcm@gmail.com Author Lodge, D. Jean 0000-0003-4807-348X Department of Plant Pathology and Odum School of Ecology, University of Georgia, Athens, GA 30602, United States & dlodgester @ gmail. com; https: // orcid. org / 0000 - 0003 - 4807 - 348 X dlodgester@gmail.com Author Margaritescu, Simona 0000-0001-5560-8847 Department of Natural History, Royal Ontario Museum, 100 Queens Park, Toronto, ON M 5 S 2 C 6, Canada & margaritescu. simona @ gmail. com; https: // orcid. org / 0000 - 0001 - 5560 - 8847 margaritescu.simona@gmail.com Author Neves, Maria Alice 0000-0002-1810-4890 Graduate Program in Biology of Fungi, Federal University of Santa Catarina (UFSC), Campus Universitário Reitor João David Ferreira Lima, s / n, 88040 - 900, Florianopolis, Brazil & maliceneves @ gmail. com; https: // orcid. org / 0000 - 0002 - 1810 - 4890 maliceneves@gmail.com Author Oliveira, Jadson J. S. 0000-0001-6643-3421 Divisão do Curso de Pós-graduação em Botânica, Instituto Nacional de Pesquisas da Amazônia (INPA), Av. André Araújo 2936, 69067 - 375, Manaus, AM, Brazil & oliveira. j. j. s. 86 @ gmail. com; https: // orcid. org / 0000 - 0001 - 6643 - 3421 oliveira.j.j.s.86@gmail.com text Phytotaxa 2023 2023-08-03 607 1 57 71 http://dx.doi.org/10.11646/phytotaxa.607.1.5 journal article 10.11646/phytotaxa.607.1.5 1179-3163 8212211 Humidicutis pindorama J.S. Cardoso, M.A. Neves & J.S. Oliveira , sp. nov. ( Figs. 3a–e , 4a–c ) MycoBank # MB844321 Etymology:—Refers to Pindorama , considered the indigenous name for Brazil in Tupi-Guarani language. Type :— BRAZIL . Santa Catarina : Itapoá , RPPN Volta Velha , Glass House Trail , 15 m elev., 26°05’23.4”S 48°38’18.5”W , 18 November 2012 , Cardoso , J . S . & Neves , M . A . 18 ( FLOR57148 , holotype ) . Diagnosis:—Basidiomata green to orange, pileus umbonate, lamellae with orange edges, stipe with orangish small fibrils, context turning bluish when cut, growing solitary in white sandy soils. Differs from Humidicutis multicolor in the lack of purple-lilac-blue pigments in the basidiomata and by having bigger basidiospores. FIGURE 3. a, b, c, d, e. Humidicutis pindorama ; a, b, c. JS485; d, e. JS18. f, g, h. Neohygrocybe fumosa (JS600). Scale = 10mm. Photos a, b, c, f, g, h by J.S. Cardoso; d, e by M.A. Neves. Description:— Pileus 22–35 mm diam., umbonate to papillate or plane with an umbo, sometimes split at the centre, smooth to finely fibrillose, moist to dry, moss green (oac41) to olive green (oac866, oac867) at the centre, becoming orange (oac838, oac775, oac789) towards the margin, hygrophanous, turning light brown (oac777) to brown (oac749) with age; margin even or slightly uplifted and splitting, sometimes eroded, translucent-striate, orange (oac761), orangy brown (oac842) with green tints, or light brown (oac799). Lamellae uncinate, subdistant, up to 3 mm broad, slightly intervenose, thick, very waxy, olive green (oac867, oac859) to moss green (oac41) near the insertion to pileus, then yellowish green (oac887) and yellowish orange (oac852, oac853) near the edge; edge entire, sometimes forking near the insertion to stipe, orange (oac761, oac789); lamellulae of two lengths. Stipe 20–50 mm × 3–4 mm , central, regular to irregular, hollow, sometimes with longitudinal fissure, dry, smooth to slightly fibrillose, green (oac40) to light green (oac67, oac851, oac21) at the apex, to yellowish (oac855) or orange (oac790, oac791) at the base, with orangish (oac845, oac810) superficial fibrils. Pileus context becoming slightly blue after cutting. Basidiomata becoming pinkorange when dried. Basidiospores 6.6– 7.98 –11 × 4– 5.61 –7 μm, Q = 1.422– 1.450 –1.470, ellipsoid, guttulate, thin-walled, hyaline, inamyloid, some germinating when still attached to the sterigmata. Basidia (29–)34–52.1 × 5.9–11 μm, cylindricclavate, funnel-shaped at the base, guttulate, hyaline, 4-spored, sterigmata up to 13.0 μm long, with conspicuous basal toruloid clamp-connections. Lamellar edge fertile. Cystidia absent. Lamellar trama regular to subregular, with parallel, slightly divergent hyphae, with some inflated segments, 33–197 × 3–40 μm, clamp connections absent. Pileipellis a cutis composed of slightly interlaced parallel hyphae, 3–9.4 μm diam., with granular encrusting pigments, some hyphae protruding, many branching or forming anastomosis, hyaline in KOH, light yellow in water, clamp connections absent. Stipitipellis a cutis of parallel hyphae 3.1–18 µm diam., cylindrical, septate, with granular encrusting pigments, with many anastomoses, upper layer of thin hair-like interwoven hyphae, 1–3.2 µm diam., protruding, hyaline in KOH, clamp connections absent. Specimens examined:— BRAZIL . Santa Catarina : Itapoá , RPPN Volta Velha , Glass House Trail , 15 m elev., 26°05’23.4”S 48°38’18.5”W , 18 November 2012 , Cardoso , J . S . & Neves , M . A . 18 ( FLOR57148 ); Cardoso , J . S . & Neves , M . A . 20 ( FLOR 57150 ); Amazonas : Manaus , Cuieiras River INPA Reserve , 20 m elev., 2°34’06.7”S 60°19’15.2”W , 12 July 2018 , Cardoso , J . S . & Vieira , S . S . 485 ( INPA285626 ) . Distribution:—Atlantic rainforest in Santa Catarina State and Amazon forest in Amazonas State . Habitat:—Growing solitary, on soil of white sand forests in both restinga and campinarana vegetation types . Comments:—There are seven green Humidicutis species described worldwide with only one recorded from South America, Humidicutis multicolor (Berk. & Broome) E. Horak (1990: 298) . Humidicutis multicolor was described from Sri Lanka with records in Tierra del Fuego , Southern Argentina , and New Zealand ( Horak 1979 , Horak 1990 ). Humidicutis multicolor also has a blue pileus context when exposed but differs from H. pindorama by having purple-lilac-blue pigments in the pileus and stipe, and by the much smaller basidiospores (5.5–7 × 4–5 µm) and basidia (20–45 × 6–7 µm) ( Horak 1990 ). Humidicutis pindorama is macroscopically like Humidicutis luteovirens (Horak) Horak (1990: 296) from New Zealand , but the latter has smaller basidiospores (6–8 × 3.5–4.5 µm) and basidia (25–42 × 6–7 µm) ( Horak 1990 ). Humidicutis arcohastata (A.M. Young) A.M. Young (2005: 159) in Australia differs from H. pindorama by the conical to campanulate pileus and by the presence of purple-mauve tints on the pileus and stipe ( Young 2005 ). Humidicutis helicoides (A.M. Young) A.M. Young (2005: 159) has lime green lamellae rather than green to orangy yellow lamellae with a deep orange edge ( Young 2005 ). Also, H. pindorama lacks the spiral bands of encrusted pigments found in the pileipellis hyphae of H. helicoides . Humidicutis taekeri (A.M. Young) A.M. Young (2005: 159) is easily distinguished from H. pindorama by its brilliant orange lamellae ( Young 2005 ). Humidicutis viridimagentea A.M. Young & K. Syme (2007: 71) differs by the distinctive magenta colouration ( Young 2005 , Young & Syme 2007 ). Finally, Humidicutis woodii (A.M. Young) A.M. Young (2005: 159) has a white stipe and lacks the conspicuous toroidal clamp connections ( Young 2005 ) at the basidia base. Only the second species of Humidicutis known from South America, H. pindorama was described based on two specimens from Southern Brazilian Atlantic Rainforest and one from the Amazon Forest, increasing the distribution range of the genus. Basidiomata were found on white sand soils, so this species is probably adapted to soils poor in nutrients. The germinating basidiospores in JS20 are very intriguing and firstly recorded herein.