Coprinopsis cerkezii – Facesoffungi number: FoF 2962

Coprinopsis cerkezii Tkalčec, Mešić, I. Kušan & Matočec

MycoBank number: MB 818295 Facesoffungi number: FoF 2962

Etymology: Described in honour of Mr. Milan Čerkez for his great contribution to the study of coprinoid and coprophilous fungi in Croatia.

Holotype: CNF 1/7253

Pileus 3–11 mm broad when expanded, spherical at first, then ellipsoid, paraboloid, convex, at maturity plano-convex with depressed centre, applanate or plano-concave, strongly plicate-sulcate up to 85% of the radius at maturity, edge strongly crenate, sometimes radially splitting with age, not hygrophanous, non-deliquescent, surface dry, at first entirely covered with upper velar layer composed of fibrils mostly directed downwards (more developed in the lower part of the pileus), tufts and warts in the central zone, upper velar layer tearing soon (mostly remaining in the form of velar patches, tufts and fibrils) and exposing whitish to cream granulose lower velar layer, fibrils white to light orange-brown, tufts and warts pale to medium orange-brown to rusty-orange, darker at centre, often paler towards the margin. Lamellae free, distant, L = 18–32, l = 0–1, up to 1.5 mm broad, sometimes forked, often deliquescent at the edge, white at first, becoming rusty-brown or dark (chocolate) brown at maturity, sometimes whitish to greyish till maturity, with whitish and flocculose edge (when not deliquescent). Stipe 10–50 × 0.5–1.2 mm, often with swollen base (up to 2 mm), slightly tapering towards the apex, central, hollow, dry, densely hairy at first, later floccose to flocculose, white to cream when young, then subhyaline, orange-brown to rusty-orange at the base, velar hairs sometimes forming volva-like basal structure. Context fragile, very thin in the pileus, whitish. Odour and taste not observed.

Basidiospores [300/6/4] (4.8–) 5.3–6.8–8.3 (–9.1) × (2.7–) 2.8–3.2–3.6 (–3.8) µm, average = 6.2–7.6 × 3–3.4 µm, Q = (1.48–) 1.66–2.12–2.59 (–2.90), Qav = 1.98–2.47 (very variable among different basidiocarps), narrowly ellipsoid, elongate ellipsoid, cylindrical or subovoid in frontal view, ellipsoid, amygdaliform, phaseoliform or allantoid in side view, smooth, moderately thick-walled (ca. 0.5 µm), with distinct and central (sometimes slightly eccentric), 1–1.5 µm wide germ-pore, rusty-brown in H₂O and NH₄OH, medium brown in KOH, non-amyloid and non-dextrinoid. Basidia 8–24 × 4–8 μm, narrowly to broadly clavate, 4-spored, thin-walled, hyaline, surrounded by 3–5 hymenophysalides (pseudoparaphyses). Hymenophysalides 10–21 × 7–18 μm, subglobose, (broadly) ellipsoid, broadly clavate or broadly oblong, thin-walled, hyaline, fully developed only in mature basidiocarps. Lamellar edge sterile with crowded cheilocystidia. Cheilocystidia 10–65 × 10–35 μm, very variable in size and shape, globose, subglobose, ellipsoid, clavate, ovoid, obovoid, conical, obtuse-conical, utriform or broadly lageniform, thin- to moderately thick-walled (up to 0.7 µm), hyaline. Pleurocystidia absent. Pileipellis a cutis, composed of repent, hyaline, thin-walled, 1.5–7 μm wide hyphae. Veil on pileus consists of two layers; lower layer completely covering pileipellis and predominantly composed of globose to broadly ellipsoid, subhyaline to pale yellow-brown, thin- to thick-walled (up to 1.2 µm), often minutely encrusted, 15–55 µm wide cells, intermixed with some hyphoid elements; upper layer tearing during the development, composed of long, (sub) cylindrical, non-diverticulate, hyaline to pale yellow-brown, thin-walled, mostly minutely to coarsely encrusted, 2–18 µm wide cells, ± intermixed with inflated (ellipsoid, fusoid, ovoid, clavate, subglobose or globose) cells, subhyaline to light yellow-brown, thin- to thick-walled (up to 1.2 µm), often minutely to coarsely encrusted, up to 50 µm wide. Stipitipellis a cutis of parallel, repent, thin-walled, hyaline, 2–12 μm wide hyphae. Veil on stipe composed of (sub) cylindrical and inflated (ellipsoid, fusoid, ovoid, clavate, subglobose or globose) cells, hyaline to light yellow-brown, thin-walled, minutely encrusted, 2–35 µm wide. Clamp connections absent.

Ecology: In groups on deer dung heaps; among mosses in forest of Abies alba, Picea abies, and Fagus sylvatica and among grasses and sedges in a thicket of Salix aurita, Betula sp., and Alnus glutinosa.

Known distribution: Croatia, mountainous area of Primorje-Gorski Kotar County, found at two localities 20 km apart.

Material examined: CROATIA, Primorje-Gorski Kotar County, near Skrad, about 1 km SE of Rogi, 4525′13″ N, 1452′59″ E, 725 m a.s.l., in forest of Abies alba, Picea abies, and Fagus sylvatica, on deer dung, 14 May 2010 in culture (substrate coll. 27 March 2010), leg. M. Čerkez (CNF 1/7253, holotype); ibid., 4525′18″ N, 1452′51″ E, 695 m a.s.l., 22 April 2010 in culture (substrate coll. 27 March 2010), leg. M. Čerkez (CNF 1/7252); CROATIA, Primorje-Gorski Kotar County, about 4 km W-NW of Fužine, 4519′16″ N, 1440′15″ E, 745 m a.s.l., among grasses and sedges, thicket of Salix aurita, Betula sp., and Alnus glutinosa, on deer dung, 13 May 2008 in culture (substrate coll. 30 April 2008), leg. M. Čerkez (CNF 1/5209); ibid., 22 May 2008 in culture (substrate coll. 30 April 2008), leg. M. Čerkez (CNF 1/5216). GenBank number ITS:KX869912.

Notes: Based on a megablast search of NCBIs GenBank numbers nucleotide database, the closest hits using the ITS1-5.8S-ITS2 sequence for our holotype collection (CNF 1/7253, GenBank numbers KX869912) are Coprinopsis (Coprinus) cortinata (J.E. Lange) Gminder (GenBank numbers JF907847; Identities = 619/702 (88%), Gaps = 29/702 (4%)), Coprinopsis (Coprinus) bellula (Uljé) P. Roux & Eyssart. (GenBank numbers FN430682; Identities = 621/705 (88%), Gaps = 30/705 (4%), and Coprinopsis utrifer (Watling) Redhead, Vilgalys & Moncalvo (GenBank numbers FN396410; Identities = 609/688 (89%), Gaps = 28/688 (4%)). Other three collections of C. cerkezii (CNF 1/5209, 1/5216, 1/7252) have identical ITS and LSU sequences. The phylogenetic analysis using maximum likelihood method was performed with MEGA6 software. The ITS sequence from the holotype of Coprinopsis cerkezii was combined with sequences of all closely related species and some other taxa of the genus Coprinopsis downloaded from GenBank number database. Analysed sequences belong to the species from subsections Alachuani, Atramentarii, Lanatuli, Narcotici, and Nivei (Uljé 2005) of the genus Coprinus sensu lato, as well as to a few Coprinopsis species transferred from the genus Psathyrella (Örstadius et al. 2015). Sequences of Coprinellus species (C. xanthothrix (Romagn.) Vilgalys, Hopple & Jacq. Johnson and C. domesticus (Bolton) Vilgalys, Hopple & Jacq. Johnson) were used as outgroup. In phylogenetic analysis Coprinopsis cerkezii clustered with other members of subsect. Nivei of the genus Coprinus sensu lato, in accordance with its morphological characters.

Coprinopsis cerkezii is primarily characterised by small and delicate basidiocarps, a strongly plicate-sulcate pileus with an orange-brown to rusty-orange upper veil, narrow and elongated spores without myxosporium, an abundance of spherical pileal velar elements lacking nipple-shaped warts, an absence of pleurocystidia and clamp-connections, and by living on dung. Comparison of C. cerkezii with similar taxa is based on descriptions in the following literature: Bisby et al. 1929; Orton and Watling 1979; Pegler 1986; Doveri 2004; Uljé 2005. Five species morphologically similar to C. cerkezii, C. bellula, C. candidata (Uljé) Gminder & T. Böhning, C. coniophora (Romagn.) Redhead, Vilgalys & Moncalvo, C. cortinata, and Coprinus furfurellus (Berk. & Broome) Pegler, differ by living on soil or wood, by presence of clamp-connections, and by absence of orange-brown tones in pileus. From above mentioned species, Coprinus furfurellus possess the most similar basidiospores (6–7 × 3.5–4 µm), but the average Q is smaller (1.73). Three other similar species live on dung as Coprinopsis cerkezii. Coprinus parvisporus Buller differs by having white pileus, less elongated spores (6 × 3.5 µm), presence of pleurocystidia, and larger spherical elements of pileal veil (60–80 µm). Coprinopsis pseudcortinata (Cacialli, Caroti & Doveri) Doveri, Granito & Lunghini differs by having white to greyish pileus, broader (3.5–4.5 µm) and less elongated spores (Q = 1.5–2.05), presence of pleurocystidia and smaller number of lamellae (L = 6–12). Coprinopsis utrifer differs by having broader (4–5.5 µm) and less elongated spores (Q = 1.3–1.7) and by presence of clamp-connections and pleurocystidia. ITS Sequences of Coprinopsis candidata, C. pseudcortinata, Coprinus furfurellus, and C. parvisporus are not included in phylogenetic analysis since the sequences of these species are not present in GenBank.