Exidia candida Lloyd

Abstract

Exidia candida Lloyd, Mycological Writings 5: 620, 1916 Fig. 16 D, E = Exidia villosa Neuhoff, Pilze Mitteleuropas 2: 22, 1935. Neotype (designated by Spirin et al. 2018: 5). Norway. Oslo: Bygdøy, Dronningberget, Tilia cordata, 3 May 2016, Spirin 10012 * (O, studied). = Exidia cartilaginea S. Lundell & Neuhoff, Pilze Mitteleuropas 2: 19, 1935. Lectotype (selected by Spirin et al. 2018: 7). Sweden. Uppland: Bondkyrka, Vårdsätra, Betula sp., 18 Oct 1932, Lundell (Fungi Exsiccati Suecici # 263) (UPS F-010986, studied). Lectotype (selected by Spirin et al. 2018: 5). USA • Washington: Clallam Co., Sequim, [no collecting date], Grant (BPI 701884, studied) (Fig. 16 D, E). Description. Basidiomata annual, at first cushion-shaped or adpressed-orbicular, up to 5 cm in diam., broadly attached, later partly fusing together and forming compound cerebriform basidiomata, up to 20 cm in the longest dimension and 2 cm thick, gelatinous. Hymenial surface uneven or folded, occasionally bearing regularly arranged spine-like projections up to 0.3 mm long, white to cream-coloured or pale ochraceous-brownish, sometimes darker, reddish-brown, in dry condition darkening to brown or brownish-black. Abhymenial surface smooth, concolourous with hymenial surface. Margin sharply delimited, elevated, concolourous with hymenial surface, or adnate, fimbriate, whitish and gradually thinning. Hyphal structure monomitic, hyphae clamped; context hyphae hyaline, thin-walled or with a distinct wall, interwoven, anastomosing, 0.5–5 μm in diam., subhymenial hyphae hyaline or yellowish, thin-walled or with a distinct wall, predominantly interwoven, 1.5–4 μm in diam., basidia-bearing hyphae 2–4 μm in diam., often showing a zigzag-like branching pattern. Hyphidia with a hyaline or yellowish, hyphoid or narrowly clavate stem, 2.5–6 μm in diam., and hyaline or yellowish apical branches, 1–2 μm in diam., forming a continuous layer up to 40 μm thick. Probasidia clavate or tapering, 10–22 × 4–7 μm. Basidia four-celled, predominantly embedded, ellipsoid-ovoid, occasionally distinctly tapering to the base, (12 –) 12.5–18 (– 21) × (7.8 –) 7.9–11.3 (– 11.4) μm (n = 30 / 3), sometimes obliquely septate, sterigmata up to 30 × 2–2.5 μm. Basidiospores narrowly to broadly cylindrical, distinctly curved, (8.7 –) 8.9–15.2 (– 15.6) × (3.1 –) 3.2–5.2 (– 5.3) μm (n = 240 / 8), L = 10.23–12.40, W = 3.97–4.55, Q = 2.35–3.12. Remarks. Exidia candida was described from the US North-West (Lloyd 1916) and recently reinstated by Spirin et al. (2018). Here we redescribe it based on a larger set of specimens from the northern hemisphere. The species is macroscopically very variable. Its darker-colored forms with a well-developed epihymenial membrane were assigned to var. cartilaginea (Spirin et al. 2018). This variety occurs mainly in the northern areas of Eurasia. The southern, “ typical ” variety (= E. villosa) is lighter-coloured, softer and it often (but not always!) bears sharp outgrowths on the hymenial surface. This feature, as well as its shorter and wider basidiospores help to separate E. candida from the superficially similar D. repanda. Phylogenetically, E. candida is more closely related to the effused Exidia spp. (E. delita, E. japonica, E. plumbescens) than to other members of the genus with reflexed basidiomata (Figs 1, 2).

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