Cystogloea oelandica: an unusual new auricularioid species from Sweden PETER ROBERTS Mycology Section, Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK p.roberts@rbgkew.org.uk R o b e r t s P.: Cystogloea oelandica: an unusual new auricularioid species from Sweden. Acta Mycol. 41 (1): 25 28, 2006. Cystogloea oelandica, a new species and genus of auricularioid fungi (Basidiomycota, incertae sedis), is described from the Swedish island of Öland. Key words: Basidiomycota, heterobasidiomycetes, parasitic fungi INTRODUCTION Whilst examining collections brought back from a field trip to the Swedish island of Öland in 2001, an undescribed auricularioid fungus was found with gelatinous basidiomes and unusual, deciduous probasidia arising from disarticulating hyphal compartments. This new species is described in a new genus, as follows: DESCRIPTION OF GENUS AND SPECIES Cystogloea P. Roberts gen. nov. Basidiomata gelatinosa. Hyphae in matrice gelatinosa, moniliformes, disarticu- lantes, in typo generis efibulatae. Probasidia ex hyphis disarticulatis constata, tenu- itunicata. Epibasidia cylindracea, septata. Basidiosporae in typo generis oblongae. Typus generis: Cystogloea oelandica P. Roberts The new genus is distinguished by producing gelatinous basidiomes in which au- ricularioid basidia arise from conspicuous probasidia which develop from disarticu- lated segments of moniliform hyphae. ACTA MYCOLOGICA Vol. 41 (1): 25-28 2006 Dedicated to Professor Alina Skirgiełło on the occasion of her ninety fifth birthday 26 P. Roberts Cystogloea oelandica P. Roberts sp. nov. Basidiomata gelatinosa, hyalina, pustulata, 1 - 2 mm lata. Hyphae in matrice gelatino- sa, moniliformes, disarticulantes, efibulatae. Probasidia ex hyphis disarticulatis constata, plerumque subglobosa vel ellipsoidea, c.15 - 20 x 12 - 17 µm, saepe oblonga vel cylin- drica, fusiformes, c. 25 - 40 x 8 - 10 µm, tenuitunicata. Epibasidia cylindracea, 45 - 60 x 5 - 7 µm, terseptata. Sterigmata 4 - 10 (- 18) µm longa. Basidiosporae oblongae, 8 - 10.5 x 5.5 - 6.5 µm. HOLOTYPUS: SWEDEN, Öland, on Quercus twig with Pseudotrichia minor on old stromata of Amphiporthe leiphaemia, 4 June 2001, B.M. Spooner, K(M) 137630. Basidiomes gelatinous, hyaline, erumpent, irregularly pustular, 1 – 2 mm across, of- ten coalescing. Hyphae in a soft, gelatinous matrix; disarticulating and only visible as disconnected, swollen, hyphal compartments in most basidiomes examined; where vis- Fig. 1. Cystogloea oelandica. (left to right) moniliform hyphae; disarticulated hyphal compart ments (probasidia) starting to produce epibasidia; mature, septate epibasidia arising from collapsed hyphal compartments (probasidia); basidiospores (type specimen). Cystogloea oelandica: an unusual new auricularioid species from Sweden 27 ible, composed of branching chains of short, swollen, hyaline compartments, 10 - 35 x 6 - 17 µm, 2.5 - 3.5 µm wide at septa, lacking clamp-connexions. Hyphidia none seen. Cystidia none seen. Conidiophores none seen. Basidia arising from disarticulated hyphal segments which act as probasidia; these probasidia thin-walled, variously shaped; mostly subglobose to ellipsoid, c.15 - 20 x 12 - 17 µm, but often fusiform, oblong to cylindri- cal, c. 25 - 40 x 8 - 10 µm, and sometimes irregular; the probasidia give rise to tubular, auricularioid epibasidia, 45 - 60 x 5 - 7 µm, which become triseptate at maturity. Sterig mata 4 - 10 (- 18) µm long. Basidiospores oblong (Q = 1.4 - 1.6), 8 - 10.5 x 5.5 - 6.5 µm, germination not seen. Fig. 1. The collection consists of several dozen, small, erumpent, gelatinous basidiomes which in the field were thought to be a species of Tremella Pers. The basidiomes were growing on an oak twig, most if not all arising from perithecia of Pseudotrichia minor Munk on old stromata of Amphiporthe leiphaemia (Fr.) Butin. Microscopi- cally, all that can be seen in most mounts are loose probasidia in a gelatinous matrix, some of which are giving rise to tubular, auricularioid epibasidia bearing oblong basidiospores. Examination of apparently immature basidiomes eventually revealed branched, rhizoctonia-like chains of swollen hyphal compartments. It appears that these swollen hyphal compartments readily disarticulate and subsequently act as probasidia. No known auricularioid species appears similar. Deciduous basidia are a feature of the genus Mycogloea L.S. Olive, but in Mycogloea species it is the tubular, epiba- sidial part of the basidium that is deciduous, the probasidia (produced on normal, narrow hyphae) remaining attached (B a n d o n i 1998). Large globose to oblong probasidia are found in some species currently assigned to the genus Cystobasidium (Lagerh.) Neuhoff, e.g. C. proliferans L.S. Olive and the lichen associates C. hypogymniicola Diederich & Ahti and C. usneicola Diederich & Alstrup, but in these species the probasidia are produced on normal hyphae and are not deciduous (O l i v e 1952; D i e d e r i c h 1996). Acknowledgment: Many thanks to Mariko Parslow for kindly examining and identifying the ascomycetes associated with Cystogloea oelandica. REFERENCES B a n d o n i R.J. 1998. On some species of Mycogloea. Mycoscience 39: 31 36. D i e d e r i c h P. 1996. The lichenicolous heterobasidiomycetes. Bibl. Lichenol. 61: 1 98. O l i v e L.S. 1952. A new species of Cystobasidium from New Jersey. Mycologia 64: 564 569. Cystogloea oelandica: niezwykły, nowy, auricularioidalny gatunek ze Szwecji S t r e s z c z e n i e Praca zawiera opis rodzaju i gatunku Cystogloea oelandica zebranego w 2001 roku na Wy spach Alandzkich w Szwecji. 2014-01-01T11:43:15+0100 Polish Botanical Society