Lichenologist 35(2): 125–135 (2003) doi:10.1016/S0024-2829(03)00014-8 Notes on the genus Polycoccum (Ascomycota, Dacampiaceae)in Spain, with a key to the species Violeta ATIENZA, Vicent CALATAYUD and David L. HAWKSWORTH Abstract: Comments on and a key to the 13 Polycoccum species known in Spain are presented, including synopses of their world distributions. Amongst these is P. rubellianae sp. nov., a lichenicolous fungus growing on thalli of Caloplaca rubelliana in eastern Spain (Valencia). It has relatively small ascomata, the lower part pale brown, and also small ascospores which are coarsely verrucose and have a thick gelatinous sheath when young. The new species is associated with a Phoma-like anamorph. The identity and systematic position of P. opulentum requires further study as the name has been applied to di#erent species, and the occurrence of P. marmoratum in Spain is in need of confirmation. The Spanish record of P. arnoldii on Lecania cyrtella probably refers to another yet undescribed species. 2003 The British Lichen Society. Published by Elsevier Science Ltd. All rights reserved. Key words: Caloplaca, Dothideales, galls, lichenicolous fungi, lichens, Valencia. Introduction accepted 23 species. Their work facilitated The genus Polycoccum Sauter ex Ko¨rb. studies on the genus, and since that time 14 (Ko¨rber, 1865) includes lichenicolous fungi additional species have been discovered with dark perithecioid ascomata, a pseudo- (Diederich, 1990; Hawksworth, 1994; parenchymatous exciple composed of dark, Calatayud & Rico, 1995; Matzer, 1996; angular polyhedral cells, and fissitunicate Aptroot et al., 1997; Hawksworth & asci with brown one-septate ascospores, and Mia¸dlikowska, 1997; Calatayud & persisting branched and anastomosed inter- Rambold, 1998; Etayo & Diederich, ascal filaments. Species of this genus mainly 1998; Navarro-Rosine´s & Roux, 1998; form commensalistic symbioses with their Kocourkova` & Berger, 1999; Calatayud & host lichens, and often produce characteris- Atienza, 2000; Va´czi & Hawksworth, 2001). tic gall-like structures on the host thallus. Twelve species of Polycoccum have pre- Most appear to be confined to a single host viously been reported from Spain (excluding lichen or a group of related species. the Canary Islands), growing on various A synopsis of the genus was provided saxicolous, terricolous, and more rarely by Hawksworth & Diederich (1988), who corticolous lichens. Three species have re- cently been described from Spain, and a further new species is described here. Com- V. Atienza: Departament de Bota`nica, Facultat de ments on and a key to all Polycoccum species Cie`ncies Biolo`giques, Universitat de Vale`ncia, Dr. reported from the Spanish mainland are Moliner, 50, ES-46071 Burjassot, Vale`ncia, Spain. V. Calatayud: Fundacio´n CEAM, Calle Charles R. provided. Darwin 14, Parc Tecnolo`gic, ES-46980 Paterna, Vale`ncia, Spain. D. L. Hawksworth: Departamento de Biologı´a Vegetal Material and Methods II, Facultad de Farmacia, Universidad Complutense, Plaza de Ramo´n y Cajal, Ciudad Universitaria, The material was examined by standard microscopic ES-28040 Madrid, Spain. techniques, and drawings were made with the aid of a 0024-2829/03/020125+11 $30.00/0 2003 The British Lichen Society. Published by Elsevier Science Ltd. All rights reserved. 126 THE LICHENOLOGIST Vol. 35 drawing tube. Amyloid reactions were tested using or distichously arranged in the asci, ellip- Lugol’s iodine solution (I), with and without pre- soid, obtuse, 1-septate, not constricted at treatment with KOH. Ascospore measurements were made in water; absolute extreme values are given in the septum except in the oldest ones, both parentheses, means in italics, and the other values are cellsequal in size, sometimes the lower extremes after rejecting 10% of the highest and 10% of one slightly narrower, with a thick gelatinous the lowest values. sheath when young, almost disappearing Additional specimens examined. Polycoccum rugulo- in mature ascospores, dark brown, thick- sarium (Lindsay) D. Hawksw.: Antarctica: South walled, coarsely verrucose when mature, Shetland Islands: King George Island, Penguinera O¨ stl. Station, on Caloplaca regalis, 21 xi 1984, L. Kappen (10–)11–12·7–14(–15) (5·5–)6–6·3–7 µm, A751 (IMI 317261). P. clauzadei Nav.-Ros. & Cl. length/width ratio (1·.7–)1·6–2–2·3(–2·7) Roux: France: Vaucluse: Buoux, La Bastide-Neuve, (67 ascospores measured). sur tuiles expose´es au N, 500 m, 9 vi 1950, G. Clauzade Conidiomata pycnidial, occasionally (MARSSJ 80—holotype). present, 30–70 µm diam., brown. Conidi- omatal wall pseudoparenchymatous, brown, The New Species composed of two to three cell layers, wall cells 63·5 µm in vertical section. Conidio- Polycoccum rubellianae Calatayud and genous cells arising from the pseudoparen- V. Atienza sp. nov. chymatous tissue, cylindrical to shortly Polycoccum rugulosarium (Lindsay) D. Hawksw. similis, ampulliform, colourless, 6–8·52–2·5 µm; sed ab eo di#ert praecipue in ascosporis latis et plus conidiogenesis enteroblastic. Conidia arising verruculosis. Fungus in thallis lichenibus Caloplaca singly, hyaline, simple, bacilliform, rounded rubelliana vigens. Ascomata subglobosa, immersa, atra, c. 85–120 µm diametro. Asci subcylindrici, 8-spori, at apex, smooth walled, 3–4·5 1–1·5 µm. c. 40–5610–14 µm. Ascosporae distichae in asco, ellipsoideae, uni-septatae, brunneae, verrucosae, Ecology and distribution. So far, the new (10–)11–12·7–14(–15)(5·5–)6–6·3–7 µm. species has been detected exclusively in the Typus: Spain, Comunidad Vale`nciana, Ga´tova, thallus of C. rubelliana. Since the areoles of close to the town, UTM 30SYK1206, on Caloplaca rubelliana, on sandstone, 700 m, 2 February 1998, this lichen infected by Polycoccum rubellianae V. Calatayud (VAB-Lich. 15244—holotypus). become slightly bullate, and are not marked by appreciable necrosis or discolouration, (Figs 1, 2) this fungus is regarded as a commensalistic species. The thalli of C. rubelliana which Ascomata perithecioid, immersed, with were abundantly infected by P. rubellianae only the ostiole and surrounding zone exter- grew close to ones of C. irrubescens. Interest- nally visible, 3–10 per areole, the infected ingly, the thalli of C. irrubescens were not areoles becoming slightly bullate, without infected by the lichenicolous fungus, sug- producing necrosis or bleaching, subglo- gesting that P. rubellianae is selective with bose, c. 85–120 µm wide. Ascomatal wall regard to its host species even within the pale brown at the base, c. 5–8 µm thick, and same genus. The new species is known only markedly darker, dark brown, and thickened from three collections from the Communi- in the upper part, up to 30 µm; in vertical dad Valenciana in eastern Spain. The host section composed of several layers of radially Caloplaca is essentially a Mediterranean compressed cells; in superficial view, cells species with outlying sites in central Europe; elongated towards the ostiole; cells in eastern Spain it occurs sporadically below c. 3·54·5 µm thick. Interascal filaments 1000 m, on hard siliceous sandstone in numerous, septate, branched and anasto- sunny situations. mosing, c. 1.5–2.5 µm thick. Hymenial gela- tine I. Asci subcylindrical, short-stalked, Remarks. Polycoccum rubellianae is pri- fissitunicate, without a distinct ocular marily characterised by the relatively small chamber, mature asci 8-spored, c. 40– ascomata, the lower part pale brown, and 5610–14 µm, not reacting in Lugol’s the narrow ascospores with a coarsely iodine solution. Ascospores monostichously granular (verrucose) surface. The presumed 2003 Polycoccum in Spain—Atienza et al. 127 F.1.Polycoccum rubellianae (holotype). A, infected host thallus; B, vertical section of an ascoma; C, ascus; D, surface view of the ascospores showing the wall ornamentation; E, interascal filaments; F, vertical section of a conidioma showing conidiogenous cells and conidia. Scales: A=1 mm; C–E=10 µm; B & F=20 µm. anamorph is Phoma-like, as in P. decolorans parts of the ascomata being brown, having (Calatayud & Rambold, 1998) rather than larger asci 60–8017–20 µm, and narrower Cyclothyrium-like as in P. peltigerae (van de ascospores (10–)12–15(–16)(4–)4·5–6 Aa, 1989). Another Polycoccum species (–6·5) µm which are not as strongly orna- known on Caloplaca is P. rugulosarium mented as P. rubellianae. Two additional (Lindsay) D. Hawksw. (Hawksworth in species of Polycoccum have been described Pegler et al., 1980; Hawksworth & on Caloplaca: P. tinantii Diederich (on C. Diederich, 1988), a lichenicolous fungus ferruginea), with much larger ascospores, primarily on Antarctic Caloplaca species, 18–267.5–11 (Diederich, 1990), and P. notably C. cirrochrooides (Vain.) Zahlbr., C. bryonthae (Arnold) Veˇzda (on C. stilli- regalis (Vain.) Zahlbr., and C. sublobulata cidiorum), a distinctive taxon which some- Nyl. That species di#ers from P. rubellianae times develops a second septum in the upper not only by occurring on di#erent host cell of the ascospores and has uniseriately species, but also by a marked preference arranged ascospores. Three further species for apothecia instead of thalli, the lower occur on other genera of Teloschistaceae: 128 THE LICHENOLOGIST Vol. 35 F .2.Polycoccum rubellianae (holotype) (in H2O). A, mature ascus; B, young ascus; C, ascospore outlines, surface ornamentation in one; D, vertical section of a conidioma showing conidiogenous cells, young and mature conidia. Scale=10 µm. P. slaptoniense D. Hawksw. (on Xanthoria Rhizocarpon) in the narrow ascospores but parietina), P. infestans (Speg.) Etayo (on in that species the ascomata are 80 µm Teloschistes flavicans), and P. clauzadei diameter, and the ascospores are shorter Nav.-Ros. & Cl. Roux (on X. elegans). The 9–11·5(–13)4·5–6·5(–7) µm with the former two species produce conspicuous lower cell somewhat tapered. Polycoccum tubercle-like galls on the thallus of the host microcarpum Diederich & Etayo (on and have larger ascomata (mainly exceeding Cladonia cervicornis) is close to P. rubellianae 200 µm diameter) than P. rubellianae. Poly- in the ascospore dimensions, but di#ers coccum clauzadei is also a cecidiogenous in that the ascomata, 30–60(–100) µm species, and di#ers from P.