Sclerococcum cladoniae, a new lichenicolous hyphomycete on Cladonia from Luxembourg

Paul Diederich

Musée national d’histoire naturelle, 25 rue Munster, L-2160 Luxembourg, Luxembourg ([email protected])

Diederich P., 2010. Sclerococcum cladoniae, a new lichenicolous hyphomycete on Cladonia from Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 111: 57-59.

Abstract. The newSclerococcum cladoniae is described from Cladonia thalli in Luxembourg. It is characterized by extremely small conidiomata, in which a mass of aseptate, brown, very small, indistinctly catenate conidia are produced.

Key words. Anamorphic fungi, Intralichen, .

1. Introduction 2. Material and Methods The Sclerococcum Fr. includes c. The material examined is deposited in BR 15 species of sporodochial anamorphic and HAL, and in the private herbarium of P. fungi, which are all lichenicolous, except Diederich. For microscopical examination, the lichenized S. griseosporodochium Etayo thin sections were examined in water and in (Etayo 1995). Although no phylogenetic 5% KOH. data are available, the genus is most proba- bly not monophyletic. The core of the genus is formed by the generic type, S. sphaerale 3. Results and Discussion (Ach.) Fr., together with several morpholog- ically similar species with black sporodochia Sclerococcum cladoniae Diederich sp. nov. (Etayo & Calatayud 1998). Several species Fig. 1 with small conidiomata and catenate conidia MycoBank 519050. were provisionally described within the Conidiomata lichenicola, sporodochia, irregular- genus, such as S. hawksworthii Etayo & Die- iter rotundata, convexa, superficialia, griseorufa, derich, S. normandinae Diederich & Etayo 7–20(–30) mm. Conidiophora semi-macrone- and S. parmeliae Etayo & Diederich (Etayo mata, e catenis conidiis ramosis irregularibus & Diederich 1995, 1996), but may eventually composita. Cellulae conidiogenae monoblasticae prove to belong to distinct genera. vel polyblasticae, integratae, terminales, rufae. Conidia indistincte catenata, sicca, acrogena, While studying the lichenicolous fungi from aseptata, subglobosa, fusca, levia, 2.2–3 μm diam. large terricolous Cladonia populations in sev- Type: Luxembourg, W of Kayl, Monument des eral parts of Luxembourg, we discovered an mineurs, alt. 370 m, over mosses in a disused apparently undescribed hyphomycete form- quarry, on Cladonia pocillum and C. subulata, 1 ing minuscule sporodochia on the host thal- Sept. 2009, P. Diederich 16826 (BR – holotype; lus, producing brown, indistinctly catenate, HAL, herb. Diederich – isotypes). aseptate conidia. The species does not resem- Colonies forming discrete, minuscule ble S. sphaerale, as conidiomata are smaller conidiomata on the host thallus; mycelium and not blackish, and conidia aseptate. We immersed, brownish, macroscopically not are not aware, however, of any more suitable visible. Conidiophores semi-macronema- genus, and therefore we describe the new tous, pale to medium brown, aggregated species in Sclerococcum, pending future phy- into irregularly rounded, convex, medium logenetic studies. Unfortunately, attempts to to dark brown or greyish brown, simple, isolate the species in pure culture failed. partly immersed to superficial sporodochia

Bull. Soc. Nat. luxemb. 111 (2010) 57 Fig. 1. Sclerococcum cladoniae (holotype). A, Squamules of Cladonia pocillum with numerous sporodochial conidi- omata; right squamule additionally with superficial mycelium of cf. Sphaerellothecium cladoniae. B–D, Sections through host thallus, showing several conidiomata. E, Same as D, after pressure on cover glass. Scale bars: A = 100 μm, B–E (same scale bar) = 10 μm.

58 Bull. Soc. Nat. luxemb. 111 (2010) of 7–20(–30) mm diam. Conidiogenous Distribution and host: The species is known cells monoblastic or polyblastic, integrated, only from the type locality in Luxembourg terminal, brown, not clearly defined, and on Cladonia pocillum and C. subulata, where the terminal cells acting in turn as conidio­ it is very common and present on almost all genous cells. Conidia irregularly adhering host thalli examined (basal squamules and in short, branched, acropetal chains, dry, podetia). It has probably been frequently subspherical, pale to medium brown, K–, overlooked owing to the extremely small aseptate, smooth-walled, thin-walled, 2.2–3 size of the conidiomata. The does not μm diam. visibly damage the host thallus. Observations: The new species is character- ized by the extremely small conidiomata, in Acknowledgements which a mass of aseptate, brown, very small, We are much obliged to Prof. Uwe Braun for criti- indistinctly catenate conidia are produced. cally commenting on the manuscript. It resembles Sclerococcum hawksworthii, S. normandinae and S. parmeliae, but is dis- References tinguished from the three by the size of the Alstrup, V., 1993. News on and licheni- conidiomata (30–100 μm in S. hawksworthii; colous fungi from the Nordic countries. Gra­ 150–300 μm in S. normandinae; and 50–120 phis Scripta 5: 96-104. μm in S. parmeliae), and by the less dis- Etayo, J., 1995. Two new species of lichenicolous tinctly catenate, aseptate and smaller conidia fungi from the Pyrenees. Nova Hedwigia 61: (they are 0–1-septate, 2.5–4 μm diam. in S. 189-197. hawksworthii; 0-septate, 4–6 × 3.5–4 μm in Etayo, J. & V. Calatayud, 1998. Sclerococcum S. normandinae; and (0–)1(–2)-septate, 7–9 (Deuteromycotina) with black sporodochia × 3.5–5 μm in S. parmeliae) (Etayo & Die- in Spain. Annalen des Naturhistorischen derich 1995, 1996). Two other known Scle­ Museums in Wien 100B: 677-681. rococcum species have aseptate conidia: S. Etayo, J. & P. Diederich, 1995. Lichenicolous simplex D. Hawksw. has larger conidiomata, fungi from the western Pyrenees, France and (50–)100–300 μm and conidia (3.5–)4–7(– Spain. I. New species of Deuteromycetes, pp. 205–221. In F. J. A. Daniels, M. Schulz & J. 8) μm (Hawksworth 1979); and S. verruci­ Peine (eds.), Flechten Follmann. Contribu- sporum Alstrup is readily distinguished by tions to Lichenology in Honour of Gerhard conidiomata up to 600 μm diam. and larger Follmann. Geobotanical and Phytotaxonom- conidia, 5–8 × 4.5–6 μm, with a verruculose ical Study Group, Botanical Institute, Univer- wall (Alstrup 1993). The new species also sity of Cologne, Cologne. resembles species of the genus Intralichen Etayo, J. & P. Diederich, 1996. Lichenicolous D. Hawksw. & M. S. Cole (Hawksworth & fungi from the western Pyrenees, France and Cole 2002), but differs by the poorly visible, Spain. II. More Deuteromycetes. Mycotaxon immersed mycelium and the sporodochial 60: 415-428. arrangement of the conidiophores. Hawksworth, D. L., 1979. The lichenicolous . Bulletin of the British Museum In the type collection, the species was some- (Natural History), Botany Series 6: 183-300. times intermixed with a sterile superficial Hawksworth, D. L. & M. S. Cole, 2002. Intrali­ mycelium probably belonging to Sphaerel­ chen, a new genus for lichenicolous ‘Bispora’ lothecium cladoniae (Alstrup & Zhurb.) and ‘Trimmatostroma’ species. Fungal Diver­ Hafellner (see Fig. 1A, right squamule). sity 11: 87-97.

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