Humidicutis pindorama J. S. Cardoso, M. A. Neves & J. S. Oliveira 2023, sp. nov.
Creators: name: Cardoso, Juli Simon
name: Moncalvo, Jean-Marc
name: Lodge, D. Jean
name: Margaritescu, Simona
name: Neves, Maria Alice
name: Oliveira, Jadson J. S.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Agaricales
Hygrophoraceae
Humidicutis
Humidicutis pindorama

description: 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.
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.
description: Published as part of Cardoso, Juli Simon, Moncalvo, Jean-Marc, Lodge, D. Jean, Margaritescu, Simona, Neves, Maria Alice & Oliveira, Jadson J. S., 2023, Studies in Hygrocybe s. l. (Hygrocyboideae, Hygrophoraceae) in Brazil: New species of Humidicutis and Neohygrocybe, pp. 57-71 in Phytotaxa 607 (1) on pages 63-64, DOI: 10.11646/phytotaxa.607.1.5, http://zenodo.org/record/8212211