Coprinopsis alnivora (Bogart) Voto, Boll. AMER, 2019

Bednár, Radovan, Červenka, Ján, Arendt, Darina, Szabóová, Dana, Greilhuber, Irmgard Krisai-, Pošta, Ana, Mešić, Armin & Tkalčec, Zdenko, 2022, Coprinopsis alnivora (Psathyrellaceae), a rare species from North America is discovered in Europe, Phytotaxa 542 (2), pp. 136-152 : 142-147

Coprinopsis alnivora (Bogart) Voto, Boll. AMER 107(2): 94 (2019) ( Figs 2–5 )

Basionym: Coprinus alnivorus Van de Bogart, Mycotaxon 4 (1): 241 (1976).

Pileus up to 55 mm high when unexpanded, 15–55 mm wide at maturity; subglobose, ellipsoid or ovoid when young, then paraboloid, campanulate or obtusely conical, finally expanded to plano-convex or applanate, sometimes slightly depressed at centre; margin sometimes radially splitting in places, mostly revolute in mature basidiomata; surface densely plicate-sulcate except in the smooth central zone, often slimy, whitish, cream or (pale) brownish at first, then starts to darken from the edge towards the centre, becoming light brown, grey-brown, often with pinkish to purplish hue, and finally brown-grey, grey or grey-black; (partially) deliquescent; when very young completely covered with a dense, usually abundant universal veil (thickest at the centre, up to 3 mm), with brownish to dark grey-brown (only rarely whitish) thin upper layer (remains scattered after veil development) and thicker white layer underneath, soon veil starting to break up into patches of different size and shape, sooner or later partially showing the pileal surface, rarely the veil poor, thin and soon disappearing. Lamellae free, very crowded and thin, L> 80, up to 14 mm broad, lamellulae present; at first white, soon becoming pinkish to purplish, brown or grey-brown with purplish tone, brown-grey, dark grey and finally black; edge whitish from prominent and very abundant cheilocystidia, deliquescent with age. Stipe 25–110 mm × 3–10 mm, (sub)cylindrical or widened towards the base (up to 20 mm), sometimes widened at the apex, dry, hollow, white to whitish, finely tomentose-squamulose (more pronounced towards the base) to silky fibrillose, sometimes with small dark olive-brown scales or fibrils in the lower part, often with adpressed ring-like veil remnants in the middle or in the lower half of the stipe or with ± projected membranaceous ring-like veil remnants near the base, without rhizomorphs. Flesh white, relatively compact when young, fragile at maturity. Smell weak, reminiscent of raw potatoes or slightly unpleasant like in Coprinopsis picacea . Taste mild. Spore print black.

Basidiospores [540/9/6] (6.8–)7.5– 8.8 –10.0(–10.5) × (5.9–)6.2– 7.1 –8.1(–8.4) × (5.1–)5.5– 6.2 –6.9(–7.4) µm, averages of different basidiomata 8.0–9.5 × 6.4–7.5 × 5.8–6.6 µm, Q f = (1.04–)1.07– 1.24 –1.42(–1.50), Q s = (1.20–) 1.25– 1.42 –1.57(–1.67), Q f av. = 1.14–1.31, Q s av. = 1.32–1.49, slightly to strongly flattened, in frontal view mostly ellipsoid to ovoid, less frequently subglobose, subangular, submitriform or sublimoniform, sometimes to rather often ± irregular (asymmetrical), with obtuse to somewhat acute base and rounded to truncate apex (especially in KOH), in side view mostly ellipsoid, much less often ± amygdaliform or ovoid, smooth, thick-walled (up to 1.4 µm), (redbrown) dark red-brown to almost black in H 2 O and NH 4 OH, (yellow-brown) dark yellowish-brown to black in KOH, germ pore central, distinct. Basidia 17–33 × 7–11 μm, clavate, 4-spored, thin-walled, hyaline, surrounded by 4–7 hymenophysalides (pseudoparaphyses); sterigmata up to 5 μm long. Cheilocystidia 25–130 × 12–38 μm, ellipsoid, elongate-ellipsoid, ovoid, fusiform, conical, with obtuse to acute apex, thin-walled, hyaline to subhyaline, abundant. Pleurocystidia 41–173 × 15–55 μm, ellipsoid, oblong, fusiform, conical, with obtuse, acute, acuminate, mucronate or somewhat irregular apex (e.g. curved or with two apical protuberances), often with one or a few short excrescences near the base, thin-walled, hyaline to pale brownish, mostly abundant. Pileipellis a cutis, composed of repent, densely arranged, thin-walled, smooth, hyaline hyphae, 3–13 µm wide. Veil hyphae 2–15(–22) μm wide, occasionally to rather frequently branched, sparsely diverticulate, thin-walled (up to 0.5 µm) or rarely moderately thick-walled (up to 0.8 µm), sometimes finely encrusted, mostly hyaline, sometimes brownish; cells occasionally constricted at the septa or somewhat inflated. Clamp-connections present, conspicuous, abundant.

Distribution and ecology:— Coprinopsis alnivora is known from 12 collections in four countries of North America and Europe: the USA, Washington State (1); Croatia (1); Slovakia (7); and Austria (3). It grows on the wood of living deciduous trees, mostly in decayed cavities or from wounds, or (less often) on dead trees, in forests and parks. Six host tree species are known so far: (a) Fagus sylvatica (on three living trees, on one dead tree— Slovakia), (b) Fraxinus excelsior (on one living tree— Slovakia), (c) Acer campestre (on one living tree— Slovakia), (d) Populus nigra (on two living trees— Croatia), (e) Alnus sp. (on a dead (?) tree— USA), (f) Magnolia salicifolia (on one living tree— Austria). It was also found in Austria on one living and one dead unidentified tree. In Slovakia, it has been observed that C. alnivora is able to fruit regularly from the same living tree over a long period of time (nine years and more).

Specimens examined: — SLOVAKIA. Bratislava region : Pezinok, Malá Homoľa, 550 m a.s.l., 48.36293° N, 17.27086° E, on living Fagus sylvatica , 11 May 2013, leg. J . Kuriplach , Ľ . Pešková , BRA CR33777 , GenBank Number : MT 887854 ; Limbach , Konské hlavy, 490 m a.s.l., 48.331944° N, 17.193250° E, in the cavity of living Fraxinus excelsior , 30 October 2018, leg. R . Bednár , BRA CR33775 , GenBank Number : MT 887857 ; Limbach , Konské hlavy, 490 m a.s.l., 48.331944° N, 17.193250° E, in the cavity of living Fraxinus excelsior , 23 October 2019, leg. R . Bednár , BRA CR33776 , GenBank Number : MT 887856 ; Kuchyňa , Vysoký Rajd, 400 m a.s.l., 48.401556° N, 17.209667° E, in the cavity of living Fagus sylvatica , 14 June 2020, leg. R . Bednár , BRA CR33778 , GenBank Number : MT 887852 ; Kuchyňa , Tri stodôlky, 520 m a.s.l., 48.422033° N, 17.208150° E, on fallen decayed log of Fagus sylvatica , 27 June 2020, leg. J . Červenka , T . Sobocký , BRA CR33779 , GenBank Number : MT 887853 ; Borinka , Úboč, 270 m a.s.l., 48.259001° N, 17.100003° E, on living Acer campestre , 7 October 2020, leg. A . Bystrická , BRA CR33781 , GenBank Number : MZ 364343 ; Trnava region : Lošonec, Zabité, 370 m a.s.l., 48.480933° N, 17.358967° E, on living Fagus sylvatica , 2 November 2019, leg. D. Solár, BRA CR33780 , GenBank Number : MT 887855 .

— AUSTRIA. Vienna: Vienna city, district Landstrasse, Botanical Garden of the University of Vienna, 180 m a.s.l., 48.19350° N, 16.38392° E, in small decayed cavity of the living deciduous tree, 31 October 2018, leg. I. Krisai-Greilhuber, WU 41009 , GenBank Number: MT 828909 ; Vienna: Vienna city, district Leopoldstadt, Prater Heustadlwasser , 170 m a.s.l., 48.20064° N, 16.26667° E, in knothole of fallen deciduous tree, 25 September 2019, leg. R. Brandstätter, WU 42007 , GenBank Number: MT 828910 ; Vienna: Vienna city, district Landstrasse , Botanical Garden of the University of Vienna, 190 m a.s.l., 48.19000° N, 16.38306° E, in decayed cavity of living Magnolia salicifolia , 24 September 2020, leg. I. Krisai-Greilhuber, WU 43426 , GenBank Number: MZ 407758 .

— CROATIA. Zagreb County: city of Zagreb, Mirogoj cemetery, 183 m a.s.l., 45.83272° N, 15.99375° E, public park, on two planted Populus nigra trees (cut down in the meantime), in decayed tree cavities, up to 1.4 m above the ground, 12 basidiomata in total, mostly a few together, in different stages of maturity, 4 October 2008, leg. M . Čerkez, CNF 1 / 5429, GenBank Number: MT 796099 .

Figures

FIGURE 2. Coprinopsis alnivora; basidiomata. A. On the same tree as BRA CR33780, 9 Sept. 2018. B. BRA CR33780. C. BRA CR33777. D. On the same locality as BRA CR33779, 27 June 2020. E. On the same tree as BRA CR33779, 27 June 2020. F. On the same tree as BRA CR33775 and BRA CR33776, 2 Oct. 2011. G. Cultivated from BRA CR33776. H–J. CNF 1/5429. Photos by: A, B D. Solár; C L. Pešková; D, E, G J. Červenka; F R. Bednár; H–J M. Čerkez.

FIGURE 3. Coprinopsis alnivora. A. Basidiospores from CNF 1/5429. B. Basidiospores from WU 42007. C. Basidiospores from BRA CR33779. D. Veil hyphae (phase contrast). E, F. Cheilocystidia. G. Pleurocystidia. Scale bars: A–C = 5 µm, D–G = 20 μm. Photos by: Z. Tkalčec.

FIGURE 4. Coprinopsis alnivora. A. Basidiospores. B. Basidia. C. Mature basidia surrounded by hymenophysalides. D. Cheilocystidia. Scale bars = 20 μm. Drawings by: J. Červenka.

FIGURE 5. Coprinopsis alnivora. A. Hyphae of universal veil. B. Secondary mycelium. C. Pleurocystidia. Scale bars = 20 μm. Drawings by: J. Červenka.