Lichenologist 31(6): 543-553 (1999) Article No. lich. 1999.0216 Available online at http://www.idealibrary.com on LECANORA COMPALLENS AND L. SINUOSA, TWO NEW OVERLOOKED CORTICOLOUS LICHEN SPECIES FROM WESTERN EUROPE C. M. van HERK* and A. APTROOTJ Abstract: Lecanora compallens and L. sinuosa, two corticolous lichens, are described as species new to science on the basis of numerous collections. Lecanora compallens is a sorediate species, known only as sterile. It is probably common in Western Europe, but overlooked because it is very similar to L. expattens. Chemically, the new species is identical with L. strobilina, of which it may represent a sorediate counterpart. Lecanora sinuosa is a new species similar to L. chlarotera and so far only known from a limited area in the Netherlands and Germany, although it may be overlooked elsewhere. Lecanora sinuosa is very close to L. hybocarpa, with which it shares the pulicaris-type epihymenium inspersed with fine crystals but differs markedly by its thick thallus and thick and sinuous apothecium margin. © 1999 The British lichen Society Introduction In the Netherlands there exists a long tradition of mapping and monitoring epiphytic lichens (Barkman 1958; de Wit 1976; van Dobben 1993). Until the 1980s, air pollution caused by sulphur dioxiode was an important reason to perform this kind of work. During the last decade, however, air pollution caused by ammonia has been a more important reason for the Dutch government to use lichens as biomonitors (van Herk 1999). A rapid change in environmental conditions during recent decades has caused a considerable increase in most of the common epiphytic lichen species (van Herk & Aptroot 1998). Several species new to science have been found during recent lichen monitoring that were not present at the investigated sites before. Among the new species is the sorediate Lecanora barkmaniana% Aptroot & van Herk (Aptroot & van Herk 1999a), a nitrophilous species favoured by ammonia pollution. Eutrophication of the bark is probably also a cause of the rapid spread of Bacidia neosquamulosa Aptroot & van Herk (Aptroot 6k van Herk 19996) and to a lesser extent of Protoparmelia hypotremella Van Herk, Spier & V. Wirth (Aptroot et al. 1997). This paper describes two additional corticolous Lecanora species. Unlike L. barkmaniana and B. neosquamulosa, the new species have probably been *Lichenologisch Onderzoekbureau Nederland, Goudvink 47, NL-3766 WK Soest, The Netherlands. JCentraalbureau voor Schimmelcultures, P.O. Box 273, NL-3740 AG Baarn, The Netherlands. §See note added at the end of this article. 0024-2829/99/060543+11 $30.00/0 © 1999 The British Lichen Society 544 THE LICHENOLOGIST Vol. 31 regular constituents of the epiphytic lichen flora for a much longer time. Until recently they were not recognized as separate species, probably because they are superficially very similar to other common species. Lecanora compallens sp. nov. is known from numerous localities, with more than 80 collections. All collections are sterile, but the morphology and chemistry strongly suggest that it belongs to Lecanora. Morphologically the new species is intermediate between L. expallens and L. barkmaniana. Chemically the new species is identical with L. strobilina (Spreng.) Kieff., of which it may represent a sorediate counterpart. Lecanora sinuosa sp. nov. was first collected in 1997 and is now known from twenty localities. Until recently it was not recognized as a separate species, probably because of its macroscopic similarity to L. chlarotera Nyl., with which it also shares the same chemistry. Microscopically, the new species resembles L. hybocarpa (Tuck.) Brodo, with which it shares the key characters separating this species from L. chlarotera, but it differs markedly in the thallus and apothecium margin. The Species Lecanora compallens Van Herk & Aptroot sp. nov. Lecanora corticola. Thallus sterilis albogriseus, zeorinum continens, sine acidio usninico. Sorediis granulosis glaucoviridis tectur, acidum usninicum et zeorinum continentes. Apothecia ignota. Habitus cum Lecanora expallens congruens. Typus: The Netherlands, Drenthe, Drouwenerveen, on Quercus robur along road, 5 March 1998, C. M. van Herk 2345 & A. Aptroot 41889 (L—holotype; ABL, hb. Van Herk, hb. Spier—isotypes, TLC). (Figs 1-2) Thallus corticolous, usually 1-3 cm diam., but sometimes covering areas of up to 5 cm diam., continuous; margin whitish grey (without usnic acid), immersed and shiny, usually with low, glaucous grey warts of 0-1-0-2 mm diam., without hypothallus; medulla below soredia 0-1-0-3 mm thick, white. Soralia always present, starting as c. 0-1-0-3 mm punctiform openings, soon uprising (not excavate) and aggregating into irregular patches, usually covering most of the thallus except for a marginal zone of c. 1 mm. Soredia granular, in a dense mass, c. 15-30 urn diam., in an up to 0-4-mm thick layer, yellowish to slightly mint-green (with usnic acid), contrasting in colour with the thallus. Herbarium specimens over one year become covered with tiny colourless needles due to recrystallization of zeorin. Apothecia and pycnidia unknown. Chemistry. Thallus C - , P D - , K - , U V - ; soredia C - , PD - , K+yellowish to yellowish brown, UV - ; usnic acid and zeorin found with TLC. Etymology. From com, together with, and (exjpallens referring to the common presence of L. expallens at the same localities. 1999 Lecanora compallens & L. sinuosa—van Herk & Aptroot 545 FIG. 1. Lecanora compallens, habitus and comparison with adjacent thalli of similar species. A, habitus with margin, isotype (Van Herk & Aptroot 41889, ABL); B, habitus with soredia, Van Herk 2179; C, adjacent thalli of L. compallens and L. barkmaniana, Van Herk 2069-9 (left: L. barkmaniana; D, adjacent thalli of L. compallens and L. expallens, Van Herk 0507-5 (left: L. expallens). Scales: A & B = 0 1 mm C & D = 0-4 mm. 546 THE LICHENOLOGIST Vol. 31 FIG. 2. Distribution of Lecanora compallens, based on herbarium specimens seen. A square corresponds to 5 x 5 km 2 . A few records from Mecklenburg-Vorpommern (former EastGermany) and Belgium are not on the map. Ecology and distribution. Usually on the west side of exposed wayside trees, especially Quercus robur, but also on Fraxinus, Populus, Salix, Sorbus, Tilia, Ulmus and even Sambucus. On Q. robur, it occurs most commonly on medium-aged (50-80 years) trees mainly on the flat surfaces of the ridges. On Salix alba, it is also found on pollarded trees. The species occurs on acid as well as neutral bark and has no critical ecology. It is not favoured by eutrophication, but avoids very acid bark. It is accompanied by a wide range of species, mainly crustose species of well-lit, exposed situations, for example, Buellia griseovirens, L. chlarotera, and Pyrrhospora quernea. At nearly all stations of the new species L. expallens is also present but both species intermingle at only a minority of its stations. The reason is that at exposed stations, favoured by L. compallens, L. expallens is usually restricted to the sheltered east side. Both species may meet at the north and south faces of the trees. At 41 monitoring stations with Q. robur the complete species composition is available, but its occurrence is apparently not highly correlated with any other species, showing that there exists no species with a comparable ecology. In circumstances with strong competition of fruticose or foliose lichens on the west side of the trees, the species may be restricted to a narrow border zone at the north and south faces. Records of L. compallens are known from the Netherlands, Germany (Weser-Ems, Mecklenburg-Vorpommern), Belgium, Great Britain (Wiltshire) and Luxembourg (Gutland). It is very common in a limited area in the northern part of the Netherlands (Fig. 2), where it sometimes covers large parts of the trunks, comparable, for example, to Pyrrhospora quernea. Elsewhere in the Netherlands it is less abundant, usually only scattered thalli being present, and hence it is easily overlooked. Small collections are available from Germany, Belgium, Great Britain and Luxembourg. 1999 Lecanora compallens & L. sinuosa—van Herk & Aptroot 547 Discussion. This new species undoubtedly belongs to Lecanora. The chemistry has been checked repeatedly (TLC was carried out on ten collections). It was found to be usnic acid and zeorin by TLC. The identity of zeorin and usnic acid have been confirmed by co-chromatography with the chemically identical L. strobilina and Cladonia diversa Asperges. This chemistry is very common in the genus, and occurs, for instance, in L. strobilina, which differs by the generally thicker, yellowish (usnic-acid-containing) thallus, the lack of regular soralia and the presence of apothecia. The new species is chemically identical with L. strobilina, though usnic acid is present only in the soredia. It may represent its sorediate counterpart. The new species is morphologically closest to L. expallens, which can be easily separated by the C +orange reaction due to the presence of thiophanic acid. It does not simply represent a chemical race of L. expallens, as there are also consistent morphological differences (see Fig. ID). Isolated thalli of L. compallens (without competition) always have a thallus margin of c. 1 mm with low glaucous grey warts. Such a wide zone is lacking in L. expallens and corticate warts are also lacking. Furthermore, L. expallens has usually excavate soralia and a more yellowish, never mint-green, colour, and sometimes a black hypothallus is present. Both species retain their separate integrity even when they grow in close mosaic-forming contact. Morphologically the new species is also close to the recently described L. barkmaniana (Aptroot & van Herk 1999<z), with which it also sometimes grows (Fig. 1C). For instance, both species have microscopically identical soredia, but L. compallens differs by the yellowish tinge of the soredia due to usnic acid, and by a much thinner, often mostly immersed, thallus. Furthermore, L. barkmaniana contains atranorin, which is lacking in L. compallens. Selected specimens examined: Germany: Weser-Ems: Oldenburgische Geest, near Westerstede, on Quercus at woodland edge, 1998, U. de Bruyn 1040 (ABL, hb. De Bruyn). MecklenburgVorpommern: Mecklenburgische Seenplatte, Malchin, west side of lake Kummerov, on Tilia in old graveyard, 1998, U. de Bruyn s.n. (hb. De Bruyn).—Great Britain: Wiltshire: Stapleford, 1972, A.M. Burnet (hb. Seaward, MRDS 102050).—Luxembourg: Gutland: Larochette, on Sorbus domestica near farm, 1998, P. Diederich 13622 (hb. Diederich).—The Netherlands: Drenthe: De Punt, on Quercus robur near farm, 1998, C. M. van Herk 2056-1, (hb. Van Herk, TLC); Eelde, Yde, on old Q. robur in village centre, 1998, C. M. van Herk 2069-9 (hb. Van Herk, with L. barkmaneana); Gasselterboerveen, on Q. robur along road, 1998, C. M. van Herk 2179 (ABL, hb. Van Herk, with L. expallens, MCT); Norgervaart, on Q. robur along canal, 1998, C. M. van Herk 2024-3, 5 (hb. Van Herk, TLC); Peize, on ancient Q. robur in graveyard, 1998, C. M. van Herk 0507-5 (hb. Van Herk, with L. expallens); Peizerwold, on Q. robur along road, 1998, C. M. van Herk 0506-10, 1 (hb. Van Herk, TLC); Ruinerweide, on Q. robur along road, 1998, C. M. van Herk s.n. (hb. Van Herk, TLC); Roden, on Q. robur along road, 1998, C. M. van Herk 0495-1, 4, 6 (hb. Van Herk, TLC); Zeijen, on Q. robur along road, 1998, C. M. van Herk 2033-3, 5 (hb. Van Herk, TLC). Flevoland: Lelystad, on Fraxinus excelsior along road, 1998, A. Aptroot 43963 (ABL). Friesland: Gaasterland, Nijemirdum, on young Quercus robur near house, 1996, C. M. van Herk 2459—2 (hb. Van Herk, TLC). Groningen: Leek, between Enumatil and Midwolde, on Ulmus along road, 1977, A. Aptroot 584 (ABL, hb. Van Herk, MCT); Noordhorn, on Populus along road, 1998, C. M. van Herk s.n. (hb. Van Herk). Noord-Holland: Midwoud, on Ulmus along road, 1998, C. M. van Herk s.n. (hb. Van Herk); Haarlem, on Populus in coastal sand dunes, 1998, C. M. van Herk s.n. (hb. Van Herk, TLC). Utrecht: Leusden-Centrum, on Q. robur along road, 1998, C. M. van Herk 4017-SBO (hb. Van Herk, TLC). Zuid-Holland: Dordrecht, Biesbosch, Otter, 548 THE LICHENOLOGIST Vol. 31 on pollarded Salix alba along ditch, 1998, A. Aptroot 42031 (ABL, MCT). Belgium: Namur. Nismes, on Tilia along road, 1999, A. Aptroot 44702 (ABL). Lecanora sinuosa Van Herk & Aptroot sp. nov. Lecanora corticola. Thallus albogriseus, verrucosus, sinuato-rimosus. Apothecia sessilia, marginibus sinuosibus, discis pallidobrunneis. Epihymenium, cortex marginis et amphithecium typis pulicaris sensu Brodo (1984). Ascosporis 13-17 x 7-5-9 \im, pachydermatis. Atranorinum et gangaleoidinum continens. Typus: The Netherlands, Drenthe, Hoogeveen, Nieuweroord, Verlengde Hoogeveensche Vaart, on Quercus robur along road near canal, 5 March 1998, C. M. van Herk 2232-1, 6 & A. Aptroot 41891 (L—holotype; ABL, hb. Van Herk—isorypes, TLC). (Figs 3-4) Thallus corticolous, usually 1-3 cm diam., continuous, whitish grey to grey, verrucose, mostly covered with raised warts of 0-1-0-4 mm diam. and 0-1-0-3 mm high, with sinuous outlines and/or cracks, resembling and homologous to the thalline margins of the apothecia, without hypothallus. Apothecia sessile, numerous, disc concave to flat, pale to medium brown, 0-4-1 -0 mm diam., margin raised, relatively thick, often incurved, whitish grey to grey, 0-1-0-3 mm wide and high, with sinuous outlines, resembling and homologous to the thallus warts, corticate with a gelatinous c. 12-18 um thick cortex, which is up to 25 um thick at base [cortex pulicaris-type sensu Brodo (1984)], with chlorococcoid algae (mostly just below the cortex) and copiously filled with 15-70 um large, hyaline, angular packets of crystals [amphithecium pulicaris-xype sensu Brodo (1984)], PD — . Hymenium hyaline, medium brown (in section) in upper 6-9 um, 60-85 um high, copiously or sparsely filled with tiny, pale brownish crystals between the paraphyses [epihymenium pulicaris-type sensu Brodo (1984)]. Hypothecium hyaline, copiously filled with chlorococcoid algae and with 15-70 um large, hyaline, angular packets of crystals. Ascospores hyaline, ellipsoid to broadly ellipsoid, 13-17 x 7-5-9 um, average 15-0 x 8-0 um («=50), wall c. 0-7 um thick. Pycnidia unknown. Chemistry. Thallus C — , PD —, K+yellow, UV — ; atranorin (constant) and gangaleoidin (in part of the collections) found with TLC. Etymology. From sinuous, wavy, referring to the incurved apothecium margin and thallus warts with a sinuous outline. Ecology and Distribution. The species has mainly been found on well-lit and exposed wayside Q. robur trees, but once on Ulmus. It occurs most commonly on medium-aged to old trees, often being found on the relatively dry east face. The species occurs on slightly acid bark and probably has a rather critical ecology. The species is not favoured by eutrophication, although it tolerates a relatively high level of eutrophication. It is accompanied by a wide range of lichens, mainly crustose species of well-lit situations, for example, Haematomma ochroleucum, Lecanora horiza, Parmelia acetabulum, Pertusaria coccodes and Phlyctis argena (Table 1). Stations with L. sinuosa are often 1999 Lecanora compallens & L. sinuosa—van Herk & Aptroot 549 FIG. 3. Lecanora sinuosa, Van Herk 2080-1, 3, 4. A, habitus with margin; B, apothecia; Q section through apothecium; D, hymenium with ascospores. Scales: A = l mm B = 0-l mm; C - 4 0 u m ; D=10um. 550 THE LICHENOLOGIST Vol. 31 FIG. 4. World distribution of Lecanora sinuosa, based on herbarium specimens seen. A square corresponds to 5 x 5 km2 extremely rich in species (average of 33-5 species per site). Lecanora sinuosa occurs in a limited area in the northern part of the Netherlands and adjacent Germany (Fig. 4), where it seems to be relatively rare. Discussion. This new species undoubtedly belongs to the Lecanora subfusca group. Several regional revisions of this group exist, for example Brodo (1984) for North America, Lumbsch (1994) for Australasia and Poelt & Vezda (1981) for Europe. However, the present species is not treated in any of these revisions, nor in any of the recent lichen floras (e.g. Purvis et al. 1992). In chemistry and in apothecial characters, the species superficially resembles several other corticolous Lecanora species, especially L. chlarotera, which differs by the chlarotera-type epihymenium and the more regular and relatively thinner apothecium margin. Microscopically, the new species resembles L. hybocarpa, with which it shares the pulicaris-type epihymenium inspersed with fine crystals separating both species from L. chlarotera, but from which it differs markedly by the thallus, which is thinner in L. hybocarpa, and by the apothecium margin, which is more regular and relatively thinner in L. hybocarpa. There is also a difference in chemistry, with gangaleoidin present in addition to atranorin in two {Aptroot 42121 and van Herk 0567-1, 2) out of eight collections tested by TLC of L. sinuosa, but this is not significant, as the presence or absence of gangaleoidin in the L. subfusca-group is quite variable at species level, illustrated by Brodo (1984: Table 5), who notes that this substance is 1999 Lecanora compallens & L. sinuosa—van Herk & Aptroot TABLE 1. Lichen composition of 16 roadside sample plots with Lecanora sinuosa in the Netherlands* Species Anaptychia ciliaris Bacidia arnoldiana s. lat. Buellia griseovirens B. punctata Calicium viride Candelaria concolor Candelariella vitellina C. xanthostigma Cladonia fimbriata Cliostomum griffithii Diploicia canescens Evernia prunastri Fellhanera subtilis Haematomma ochroleucum var. porphyrium Hypocenomyce scalaris Hypogymnia physodes H. tubulosa Lecanora barkmaniana L. carpinea L. chlarotera L. compallens sp. nov. L. conizaeoides L. dispersa L. expallens L. hageni L. horiza L. muralis L. pulicaris L. saligna L. sinuosa sp. nov. L. symmicta Lecidella elaeochroma L. flavosorediata L. scabra Lepraria incana Micarea denigrata M. nitschkeana Ochrolechia androgyna O. turneri Opegrapha atra O. niveoatra Parmelia acetabulum P. caperata P. elegantula P. exasperatula P. glabratula P. laciniatula P. revoluta P. saxatilis Number of plots where present 1 10 16 16 1 1 9 2 5 5 2 13 2 11 3 11 3 3 10 16 8 8 3 16 2 7 3 8 1 16 1 14 5 2 16 1 1 8 2 2 2 15 1 1 4 2 1 7 6 Continued 551 552 THE LICHENOLOGIST Vol. 31 TABLE 1. Continued Species P. subaurifera P. subrudecta P. sulcata P. tiliacea Pertusaria albescens P. amara P. coccodes P. pertusa Phaeophyscia orbicularis Phlyctis argena Physcia adscendens P. caesia P. dubia P. tenella Physconia enteroxantha P. grisea Protoparmelia hypotremella P. oleagina Pseudevernia furfuracea Pyrrhospora quemea Ramalina farinacea .R. fastigiata /?. fraxinea i?. lacera Schismatomma decolorans Trapeliopsis granulosa Xanthoria candelaria X. parietina X. polycarpa Number of plots where present 15 12 16 1 6 5 8 5 2 16 4 7 2 16 3 4 2 5 6 10 16 16 4 1 5 1 14 15 16 *At each site usually ten Quercus robur trees were investigated. Data was collected by the first author during a mapping programme at the request of the Dutch government. inconstant in nearly half of the species he reports it from; often somewhat correlated with geography. The identity of atranorin and gangaleoidin has been proved by co-chromatography with L. gangaleoides Nyl. The new species has been compared with numerous specimens of L. hybocarpa from Canada, U.S.A., Portugal (all in ABL), Germany (Eifel, Budesheim, 1998, A. Aptroot 42861, ABL, which is the first report of this species from Germany) and Belgium (hb. Brand), which were all in full agreement with the descriptions in Brodo (1984) and Giralt (1996), and consistently different. Other species that are reminiscent in some respects, but which are more distant from L. sinuosa, are L. subrugosa Nyl., which has a pigmented, not granulose epipsamma (epihymenium glabrata-type), L. meridionalis H. Magn., which has nearly black apothecia (epihymenium chlarotera-type or gangaleoides-type) and L. rugosella Zahlbr., which has a coarsely granular epipsamma (epihymenium chlarotera-type). 1999 Lecanora compallens & L. sinuosa—van Herk & Aptroot 553 Selected specimens examined: Germany: Niedersachsen: Ostfriesland, Westerstede, Wiefelstede, on Quercus near farm, 1998, A. Aptroot 42121 & C. M. van Herk s.n. (ABL, hb. Van Herk, with L. chlarotera, TLC).—The Netherlands: Drenthe: Beilen, on old Q. robur near farm, 1997, C. M. van Herk 0567-1, 2 (hb. Van Herk, TLC); De Groeve, on Q. robur in village, 1998, C. M. van Herk 2085-2 (hb. Van Herk, TLC); De Punt near Eelde, on Q. robur along road, 1998, C. M. van Herk 2055-1 (hb. Van Herk, TLC); Eelderwolde, on old Q. robur along road, 1998, C. M. van Herk 2080-1, 3, 4 (hb. Van Herk, TLC); Nijeveen, on ancient Q. robur in the village, 1997, C. M. van Herk 0027-6 (ABL, hb. Van Herk, with L. chlarotera, TLC); Peize, on roadside Q. robur, 1998, C. M. van Herk 0501-1, 5 (hb. Van Herk, TLC). Groningen: Aduard, Nieuwklap, on Ulmus along road, 1998, C. M. van Herk s.n. (hb. Van Herk). We thank Leo Spier for T L C of the species and the administration of the provinces of Groningen, Friesland, Drenthe and Utrecht for placing the Dutch records at our disposal. Dr Uwe de Bruyn, Dr Paul Diederich and Professor Mark Seaward are warmly thanked for allowing us to study the cited specimens from Germany, Luxembourg and Great Britain respectively. REFERENCES Aptroot, A. & van Herk, C. M. (1999a) Lecanora barkmaneana, a new nitrophilous sorediate corticolous lichen from the Netherlands. Lichenologist 31: 3-8. Aptroot, A. & van Herk, C. M. (19996) Bacidia neosquamulosa, a new and rapidly spreading corticolous lichen species from from western Europe. Lichenologist 31: 121-127. Aptroot, A., Diederich, P. Herk, C. M. van, Spier, L. & Wirth, V. (1997) Protoparmelia hypotremella, a new sterile corticolous species from Europe, and its lichenicolous fungi. Lichenologist 29: 415-424. Barkman, J. J. (1958) Phytosociology and Ecology of Cryptogamic Epiphytes. Assen: Van Gorcum. Brodo, I. M. (1984) The North American species of the Lecanora subfusca Group. Beiheft zur Nova Hedwigia 79: 63-185. Giralt, M. (1996) Liquens Epifits i Contaminacio Atmosferica a la Plana i les Serralades Litorals Tarragonines. Thesis, Barcelona. Lumbsch, H. T. (1994) Die Lecanora subfusca-Gruppe in Australasien. Journal of the Hattori Botanical Laboratory 77: 1-175. Poelt, J. & Vezda, A. (1981) Bestimmungsschliissel europaischer Flechten. Erganzungsheft II. Bibliotheca Lichenologica 16: 1-390. Purvis, O. W., Coppins, B. J., Hawksworth, D. L., James, P. W. & Moore, D. M. (1992) The Lichen Flora of Great Britain and Ireland. London: Natural History Museum, van Dobben, H. F. (1993) Vegetation as a Monitor for Deposition of Nitrogen and Acidity. Thesis, Utrecht, van Herk, C. M. (1999) Mapping of ammonia pollution with epiphytic lichens in the Netherlands. Lichenologist 31: 9-20. van Herk, K. & Aptroot, A. (1998) Recovery of epiphytic lichens in the Netherlands. British Lichen Society Bulletin 82: 22-26. de Wit, T. (1976) Epiphytic lichens and air pollution in the Netherlands. Bibliotheca Lichenologica 5: 1-115. Accepted for publication 15 April 1999 Note added in proof: Lecanora barkmaneana should be Lecanora barkmaniana. In The Lichenologist 31: 3-8 (1999) Lecanora barkmaneana was described as new to science (Aptroot & van Herk). Unfortunately, it appears that the correct spelling, according to the International Code of Botanical Nomenclature (Art. 60.11, 60.Cl), should be Lecanora barkmaniana. We apologise for the confusion caused, although we like to point out that the name originally proposed was Lecanora barkmanii, and the change to (the incorrect) barkmaneana was suggested by one of the anonymous referees. Although the description is valid, researchers are advised to use the correct spelling.