Coprinopsis floccosa Schünemann & Westphalen & Díazvalderrama & Aguilar & Silveira 2023, sp. nov.
Creators: name: Schünemann, Bárbara Letícia Botura
name: Westphalen, Mauro
name: Díazvalderrama, Jorge Ronny
name: Aguilar, Vilma
name: Silveira, Rosa Mara Borges Da
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Agaricales
Psathyrellaceae
Coprinopsis
Coprinopsis floccosa

description: Coprinopsis floccosa Sch ̧nemann & R.M.Silveira, sp. nov.
FIG. 3
Mycobank: 846927
Typification: — BRAZIL. Rio Grande do Sul: Maquiné, FEPAGRO, gregarious on decayed tree, 29°39’41.0”S, 50°12’58.5”W, 27 July 2017, B. L. B. Schünemann 083 (holotype ICN 200443), Gen Bank accessions: MK843968, ON640619.
Diagnosis: —Pileus applanate grey to olive grey, powdery veil, pale grey to yellowish white, stipe covered with universal veil, turbinate to globose cheilocystidia, strongly incrusted subglobose veil elements.
Etymology: —The name floccosa refers to the kind of veil that covers the pileus.
Description: —Pileus prior to expansion 2–4 × 2–3 mm, globose to subglobose, pale grey (1A2) to yellowish white (1BA); 4–7 × 2–3 mm wide when expanded, conic to parabolic then convex to applanate, strongly plicate, grey (1D1) to olive grey (1E2), veil flocculose to powdery, pale grey (1A2) to yellowish white (1BA), very dense on umbo becoming scattered to the margin. Lamellae free, subdistant, decurved becoming revolute, at young stage pale grey (1A2) to yellowish white (1BA), at maturity dark brown (7F6), deliquescent, edge concolor. Stipe 6–9 × 0.5–1 mm, central, equal, fistulose, yellowish white (1BA) covered with concolor scattered flocculose to powdery veil. Annulus absent.
Basidiospores 5.5–8 × 4–5 × 4–5.5 μm, Q= 1.21–1.54, Qav = 1.37, ellipsoid in frontal view, smooth, dark green to grey in KOH, guttulate, thick-walled; apiculus visible; germ pore central, covered with a hyaline cap. Basidia dimorphic, short clavate 13–17 × 6–8 μm, long clavate 18–21 × 7–10 μm hyaline, often guttulate; 2-, 3- or 4-spored. Pseudoparaphyses 13–17 × 13–18 μm, hyaline, thin-walled, 3–4 surrounding the basidia. Cheilocystidia 31–33 × 22–30 μm, turbinate to globose, hyaline and thin-walled. Pleurocystidia absent. Hymenophoral trama is parallel to subparallel. Pileipellis a cutis of elongated hyphae, radially oriented, hyaline, thin-walled.Veil composed with chains of subglobose elements 150–200 μm, strongly incrusted, thin-walled, hyaline. Stipitipellis a parallelocutis with elongated and incrusted elements, thin-walled, hyaline. Clamp connections present.
Habitat and known distribution: —Growing gregarious in decayed trees of Dense Ombrophilous Forest; recorded from FEPAGRO, Maquiné (Rio Grande do Sul, Brazil).
Comments:— Coprinopsis floccosa main distinguishing features are the small basidiomata, applanate grey to olive grey pileus, the pale grey to yellowish white flocculose to powdery veil, formed by thin-walled subglobose and incrusted cells; ellipsoid basidiospores; turbinate to globose cheilocystidia and growing on decayed wood (FIG. 3).
Coprinopsis floccosa belongs to section Nivei (Schafer 2010) due to the the flocculose to pruinose veil, which is pale grey to yellowish white, and very dense on the umbo and more scattered towards the pileus margin. Based on phylogenetic results, C. floccosa belongs to the clade /Subnivea (Wächter & Melzer 2020), which can be corroborated by the small basidiomata, strongly developed veil with subglobose, and incrusted cells and absence of pleurocystidia, as described to the clade.
Coprinopsis floccosa is phylogenetically related to C. coniophora (Romagn.) Redhead, Vilgalys & Moncalvo (2001: 227) in Redhead, Vilgalys, Moncalvo, Johnson & Hopple (2001), C. cerkezii Tkalčec, Mešić, I. Kušan & Matočec (2017: 232) in Tibpromma et al., (2017), C. cortinata (J.E. Lange) Gminder (2010: 650) and morphologically similar to C. pseudocortinata (Locq. ex Cacialli, Caroti & Doveri) Doveri, Granito & Lunghini (2005: 339). C. coniophora differs in a white pileus up to 12 mm wide, amygdaliform or ovoid basidiospores and basidia always 4- spored (Uljé 2005). C. cerkezii differs in the stipe up to 50 mm long, pale orange-brown to rusty-orange veil, absence of clamp connections, and coprophilous habitat (Tibpromma et al. 2017). C. cortinata differs in the pileus with up to 15 mm wide, cheilocystidia absent and growing on grasses and soil, solitary or in small groups. C. pseudocortinata has ellipsoid basidiospores with parallel sides (6.5–10.5 x 4–6 μm), ellipsoid, utriform or subcylindrical pleurocystidia, clamp connections absent and coprophilous habitat (Uljé 2005).
description: Published as part of Schünemann, Bárbara Letícia Botura, Westphalen, Mauro, Díazvalderrama, Jorge Ronny, Aguilar, Vilma & Silveira, Rosa Mara Borges Da, 2023, Coprinopsis (Psathyrellaceae, Agaricales) in the Neotropics: three new species and a new combination, pp. 113-134 in Phytotaxa 585 (2) on pages 125-126, DOI: 10.11646/phytotaxa.585.2.3, http://zenodo.org/record/7681516