Ulocolla subrepanda Spirin 2026, comb. nov.

Abstract

Ulocolla subrepanda (P. Karst.) Spirin comb. nov. Figs 33 G, 36 G ≡ Exidia albida ssp. subrepanda P. Karst., Meddelanden af Societas pro Fauna et Flora Fennica 18: 73, 1891. Lectotype (selected by Spirin et al. 2018: 7). Finland. Etelä-Häme: Tammela, Mustiala, Picea abies, 18 Nov 1890, Karsten 2143 (H 6061344, studied). = Exidia subrepanda (P. Karst.) Oudemans, Enumeratio Systematica Fungorum 1: 398, 1919. Description. Basidiomata annual, at first cushion-shaped or adpressed-orbicular, narrowly or broadly attached, later cerebriform or almost foliaceous, up to 6 cm in diam. and 2 cm thick, gelatinous. Hymenial surface at first nearly smooth or uneven, then distinctly folded, occasionally covered by poorly visible densely arranged warts, amber-yellow to yellowish-brown, later reddish-brown, in older specimens fading to pale yellow, in dry condition brownish-black. Abhymenial surface smooth, concolourous with hymenial surface. Margin free, concolourous with hymenial surface, entire, even or indistinctly lobate. Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin- to distinctly thick-walled (walls often strongly gelatinized), interwoven, anastomosing, 1–5 μm in diam., subhymenial hyphae hyaline to yellowish, thin- to distinctly thick-walled, ascending or interwoven, 1–5 μm in diam., basidia-bearing hyphae 2–4 μm in diam. Cystidia absent. Hyphidia with a distinctly thick-walled, brownish or brown, hyphoid or nodulose (occasionally almost moniliform) stem, 2–6 μm in diam., and yellowish-brownish apical branches, 1–2 μm in diam., forming a continuous layer up to 40 μm thick. Probasidia clavate or tapering, 14–18 × 5–7 μm. Basidia thin- or slightly thick-walled, four-celled, ellipsoid-ovoid to narrowly ovoid, some with a distinctly narrowed, stalk-like base, occasionally obliquely septate, (13 –) 13.5–20 (– 20.5) × (7.2 –) 7.3–10.4 (– 10.9) μm (n = 70 / 7), sterigmata up to 15 × 1.2–1.5 μm. Basidiospores narrowly cylindrical to cylindrical, distinctly curved, (8.1 –) 8.2–13.3 (– 14.2) × (3.2 –) 3.3–5.4 (– 5.7) μm (n = 240 / 8), L = 9.96–11.33, W = 3.91–4.85, Q = 2.35–2.81. Remarks. Ulocolla subrepanda is widely distributed in the cold temperate and boreal ecosystems of Eurasia where it inhabits wood (mainly freshly fallen logs and thick branches) of various coniferous trees. Morphologically and phylogenetically, it is closely related to U. saccharina from Europe and U. pinicola from North America. It differs from U. saccharina in having smaller basidia and basidiospores. The basidiomata of U. subrepanda are also usually smaller than those of U. saccharina, and they are devoid of easily detectable hymenial projections. We could not find any reliable morphological traits separating U. subrepanda and U. pinicola. However, these species show clear differences in ITS sequences and they are distributed in different geographic areas. This species was first introduced as a variety of Exidia albida sensu auct. (Karsten 1891) and then raised to the species rank in the genus Exidia (Oudemans 1919). The type specimen was collected from Picea abies. It is completely sterile; however, the host tree and rather small basidia preclude U. saccharina s. str. (see above).

Authors 13

1. Viacheslav Spirin

   University of Helsinki · Finnish Museum of Natural History

   Affiliation as printed

   Finnish Museum of Natural History, University of Helsinki, PO Box 7, 00014 Helsinki, Finland

2. Vera F. Malysheva

   Komarov Botanical Institute of the Russian Academy of Sciences

   Affiliation as printed

   Komarov Botanical Institute, Prof. Popova str. 2, 197022 St. Petersburg, Russia

3. Nathan Schoutteten

   Universität Hamburg

   Affiliation as printed

   Organismic Botany and Mycology, Institute of Plant Science and Microbiology, Ohnhorststraße 18, 22609 Hamburg, Germany

4. Anton Savchenko Aachen Naturalis Biodiversity Center

   Naturalis Biodiversity Center

   Affiliation as printed

   Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, Netherlands

5. Bernard Rivoire
   Affiliation as printed

   Société Linnéenne de Lyon, 33 rue Bossuet, 69006 Lyon, France

6. Jan Olsson
   Affiliation as printed

   Österplana Skattegården 2, 53384 Hällekis, Sweden

7. Thomas Læssøe

   University of Copenhagen

   Affiliation as printed

   Globe Institute, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark

8. Leif Ryvarden

   University of Oslo

   Affiliation as printed

   Institute of Biological Sciences, University of Oslo, P. O. Box 1045, Blindern, N- 0316 Oslo, Norway

9. Django Grootmyers

   University of Tennessee at Knoxville

   Affiliation as printed

   Department of Ecology and Evolutionary Biology, University of Tennessee, 1406 Circle Drive, Knoxville, Tennessee 37996, USA

10. Matti Kulju

    University of Oulu

    Affiliation as printed

    Ecology and Genetics Research Unit, University of Oulu, P. O. Box 3000, FI- 90014 Oulu, Finland

11. Josef Vlasák

    Czech Academy of Sciences, Biology Centre

    Affiliation as printed

    Biology Centre, Academy of Sciences of the Czech Republic, Branišovská 31, CZ 37005, České Budějovice, Czech Republic

12. M. Victoria Vignale

    National University of Misiones

    Affiliation as printed

    Instituto de Biotecnología Misiones (InBioMis), Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Ruta Nacional N 12, km 7.5, Posadas, Misiones, CP 3304, Argentina & Instituto Misionero de Biodiversidad (IMiBio), Ruta Nacional N 12, km 5, Puerto Iguazú, Misiones, CP 3370, Argentina

13. Ilya A. Viner

    University of Helsinki · Finnish Museum of Natural History

    Affiliation as printed

    Finnish Museum of Natural History, University of Helsinki, PO Box 7, 00014 Helsinki, Finland