Feb 18, 1998 - Abstract: Lecanora barkmaneana, a sorediate corticolous lichen ... Lecanora subfusca group, is described as a species new to science on the ...
Lichenologist 31(1): 3-8 (1999) Article No. lich. 1998.0139 Available online at http://www.idealibrary.com on
LECANORA BARKMANEANA, A NEW NITROPHILOUS SOREDIATE CORTICOLOUS LICHEN FROM THE NETHERLANDS A. APTROOT* & C. M. van HERRJ Abstract: Lecanora barkmaneana, a sorediate corticolous lichen belonging to the Lecanora subfusca group, is described as a species new to science on the basis of numerous sterile collections and tworichlyfertile collections. It is known so far only from the Netherlands, where it often grows on roadside trees. It seems to be spreading rapidly at nutrient-rich sites. © 1999 The British Lichen Society
Introduction The corticolous lichen flora of roadside trees in the Netherlands has drastically changed during this century. After a steady decrease in biodiversity until the 1970s, a rapid increase in species diversity has been observed in recent decades (van Herk & Aptroot 1996). Among the increasing species some seem to be new to science (Aptroot et al. 1997). Also, an apparently new Lecanora species was first found in 1989 and initially thought to represent an undescribed Lecidella species. Now it is spreading rapidly on roadside trees in the Netherlands, where it is known from more than 60 localities. Most collections are sterile, but the holotype and one additional collection are fertile, proving that the species really belongs to Lecanora s.str., as was supposed on the basis of the sterile thallus morphology and the chemistry. The Species Lecanora barkmaneana Aptroot & van Herk sp. nov. Lecanora corticola. Thallus sterilis griseus, sorediis granulosis viridis tectur. Apothecia concava, sorediata. Acidum chloratranorinum, atranorinum et zeorinum continens. Typus: The Netherlands, Friesland, Wolvega, De Blesse, on Quercus robur along road, 9 November 1996, C. M. van Herk 2444-4 (B—holotype; ABL, hb. Van Herk—isotypes).
(Figs 1-2) Thallus corticolous, determinate, covering areas of up to 5 cm diam., continuous, whitish grey, becoming brownish grey in the herbarium after *Centraalbureau voor Schimmelcultures, P.O. Box 273, NL-3740 AG Baarn, The Netherlands. ^Lichenologisch Onderzoekbureau Nederland, Goudvink 47, NL-3766 WK Soest, The Netherlands. 0024-2829/99/010003 + 06 $30.00/0
© 1999 The British Lichen Society
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FIG. 1. Lecanora barkmaneana. A-B: holotype; C: A. Aptroot 39081. A. Apothecium with sorediate, flexuose margin; B & C. Thallus with soralia. Scale=l mm.
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several years, rimose-verruculose, warts c. 0-1-0-2 mm diam., up to 0-1 mm thick, angular to rounded, corticate, surrounded by a whitish hypothallus. Soralia always present, starting as c. 0-1-0-3 mm diam., punctiform, opening thallus warts, soon coalescent into irregular patches and usually covering most of the thallus except for a marginal zone of c. 1 mm. Soredia granular, in a dense mass, c. 15-30 um diam., in an up to 0-6 mm thick layer, pale greenish grey to pale greenish white, contrasting in colour with the thallus. Apothecia rare, sessile on the thallus but seemingly immersed between the soredia, 0-4-0-7 mm diam. Margin strongly crenulate, indistinctly corticate with a non-gelatinous c. 5-8 \im thick cortex (cortex cinereofusca-type sensu Brodo, 1984), whitish grey, often sorediate at the circumference, up to 0-2 mm wide, copiously filled with chlorococcoid algae and with 15-50 urn large, hyaline, angular packets of crystals (amphithecium pulicaris-typc sensu Brodo, 1984), PD — . Disc concave, pale brownish to buff, with some isolated whitish granules, not pruinose, C — . Hymenium hyaline to pale brownish in section, 50-75 |im high. Epihymenium with a 2-4 um high layer of tiny, pale brownish crystals on the surface, not between the paraphyses (epipsamma chlaroteratype sensu Brodo 1984). Hypothecium hyaline, copiously filled with chlorococcoid algae and with 15-50 urn large, hyaline, angular packets of crystals. Ascospores few, hyaline, long ellipsoid, 7-10 x 3-4 |am (as observed in tap water), possibly partly developed under adverse conditions, brownish when senescent. Pycnidia not observed. Algae cholorococcoid, globose, up to 15 urn diam. Etymology. Commemorates Professor Jan Johannes Barkman (1922-1990), the Dutch pioneer on the ecology and syntaxonomy of epiphytic lichens. Chemistry. Thallus C — , PD — , K+ yellow; apothecium margin PD — ; apothecium disc C —; chloratranorin and zeorin (major) and atranorin (minor) found with HPLC and TLC. Ecology and distribution. Mainly on well-lit, usually exposed wayside trees, for example Quercus robur, Populus x canadensis, Fraxinus excelsior and Ulmus
species. It occurs on old as well as young trees, preferring eutrophicated, usually dusty, rough bark. On Q. robur (acid bark) it prefers sites with strong eutrophication, e.g. ammonia pollution caused by intensive cattle breeding. Lecanora barkmaneana occurs in communities with abundant nitrophytic species. Candelariella reflexa, Phaeophyscia orbicularis, Physcia caesia and
Xanthoria polycarpa very often grow with the new species (Table 1). The new species occurs at nearly all known stations of Caloplaca herbidella and Physcia clementei in the Netherlands. Both are rare nitrophytic species. Ecologically the species is very close to Lecidellaflavosorediata,which occurs at c. 45% of the stations of the new species. Acidophytic species such as Lecanora conizaeoides and Hypogymnia physodes are relatively scarce at its stations. Discussion. This new species undoubtedly belongs to Lecanora s.str., i.e. the L. subfusca group. The chemistry has been checked repeatedly. It was found to be chloratranorin and zeorin (major) and atranorin by HPLC and TLC
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FIG. 2. Distribution of Lecanora barkmaneana in the Netherlands, based upon herbarium specimens and field records. A square corresponds to 5 x 5 km2. The field records are based on a mapping programme of approx. 6000 localities with ten trees, carried out between 1989 and 1997 by the second author.
(specimens tested: C. M. van Herk 0539 and 5157). This chemistry is common in the genus. Several regional revisions of the 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. In thalline characters, the species superficially resembles several other conicolous sorediate Lecanora species. It resembles L. variolascens Nyl. (Lumbsch et al. 1997), which, however, differs by the well-delimited, whitish grey soralia and the chemistry (e.g. psoromic acid). It differs by the confluent, greenish soralia and the pale apothecia with small ascospores from L. allophana f. sorediata (Schaerer) Vainio, L. farinaria Borrer and L. impudens Degel. From usnicacid-containing species, for example L. expallens Ach. and L. strobilina (Sprengel) Kieffer, it differs by the lack of any yellowish tinge. The species in the field is somewhat reminiscent of some forms of Buellia griseovirens (Turner
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Lecanora barkmaneana—Aptroot & van Herk TABLE 1. Lichen composition of 65 roadside sample plots with Lecanora barkmaneana in the Netherlands" Anisomeridium biforme Arthonia impolita A. radiata Bacidia arnoldiana Buellia griseovirens B. punctata Caloplaca citrina f. phlogina C. herbidella C. holocarpa Candelaria concolor Candelariella aurella C. reflexa C. vitellina C. xanthostigma Chaenotheca ferruginea Cladonia sp. Cliostomum griffithii Diploicia canescens Evernia prunastri Haemawmma ochroleucum var. porphyrium Halecania viridescens Hyperphyscia adglutinata Hypocenomyce scalaris Hypogymnia physodes Lecania cyrtella Lecanora barkmaneana L. carpinea L. chlarotera L. conizaeoides L. dispersa L. expallens L. hageni L. horiza L. pulicaris L. symmicta Lecidella elaeochroma L. flavosorediata L. scabra Lepraria incana Alicarea prasina Ochrolechia androgyna O. turneri Opegrapha atra O. herbarum O. niveoatra O. rufescens O. vermicellifera
1 1 6 37 28 65 2 3 1 20 3 46 41 25 1 15 10 9 26 9 3 6 1 7 1 65 34 57 8 24 64 21 5 2 30 59 29 5 33 1 5 4 4 2 2 1 1
O. vulgata Parmelia acetabulum P. caperata P. elegantula P. exasperatula P. glabratula P. laciniatula P. perlata P. revoluta P. saxatilis P. soredians P. subaurifera P. subrudecta P. sulcata P. tiliacea Pertusaria albescens P. amara P. coccodes P. pertusa Phaeophyscia nigricans
1 19 13 6 12 2 5 5 12 4 5 53 39 64 1 9 3 11 7 5
P. orbicularis Phlyctis argena Physcia adscendens P. caesia P. clementei P. dubia P. stellaris P. tenella Physconia distorta P. enteroxantha P. grisea Protoparmelia hypotremella P. oleagina Pseudevemia furfuracea Pyrrhospora quemea Ramalina farinacea R. fastigiata R. fraxinea R. lacera Rinodina pityrea Schismatomma decolorans Trapeliopsis flexuosa Xanthoria calcicola X. candelaria X. parietina X. polycarpa
43 16 53 42 2 19 1 65 3 5 23 3 1 1 17 45 26 3 2 1 11 1 5 61 63 62
'Nomenclature mostly follows Purvis et al. (1992). At each site usually ten trees were investigated. For each species the number of plots in which it was present is given. Mean number of species per site: 26.
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& Borrer ex Sm.) Almborn, which has a thinner and darker grey thallus, and sharper delimited, often somewhat excavate, soralia, and a different chemistry (e.g. norstictic acid). Selected specimens examined (sterile unless otherwise noted): The Netherlands (see Fig 2): Groningen: Komhorn, on Quercus along road, 1991, C. M. van Herk 2595-8 (hb. Van Herk). Friesland: Type (fertile). Drenthe: Westerbork, on Quercus at forest margin, 1997, C. M. van Herk 2191-4 (hb. Van Herk, fertile): Vledder, on Quercus along road, 1989 C. M. van Herk 0439 (BG. hb. Van Herk), 1993, A. Aptroot (ABL). Overijssel: Vroomshoop, on Quercus along road, 1994, C. M. van Herk 4577-8 (ABL, hb. Van Herk). Gelderland: Ede, on Quercus along road, 1990, C. M. van Herk 1009-3 (hb. Van Herk); Nijkerk, on Populus along road, 1997, L. Spier (hb. Spier). Utrecht: Leusden, on Quercus along road, 1996,/!. Aptroot 39081 (ABL), C. M. vanHerk5\57 (E, ESS, hb. Van Herk). Noord-Brabant: Heusden, on Quercus along road, 1993, C. M. van Herk 3151-10 (hb. Van Herk). Zeeland: Nieuwvliet, on Populus along dyke, 1997, C. M. van Herk 6576-2 (hb. Van Herk). We thank Dr B. C. Coppins for discussions on this species, Dr H. T. Lumbsch for HPLC of the species, Dr T Tansberg for TLC, and the administration of the provinces of Groningen, Friesland, Drenthe, Overijssel, Gelderland, Utrecht, Noord-Brabant and Zeeland for placing Dutch records and species composition of the sites at our disposal.
REFERENCES
Aptroot, A., Diederich, P., Herk, C. M. van, Spier, L. & Wirth, V. (1997) Protoparnielia hypotremella, a new sterile corticolous species from Europe, and its lichenicolous fungi. Lichenologist 29: 415-424. Brodo, I. M. (1984) The North American species of the Lecanora subfusca group. Beiheft zurNova Hedwigia 79: 63-185. Lumbsch, H. T. (1994) Die Lecanora subfusca-Gruppe in Australasien. Journal of the Hattori Botanical Laboratory 11': 1-175. Lumbsch, H. T., Plumper, M., Guderley, R. & Feige, G. B. (1997) The corticolous species of Lecanora sensu stricto with pruinose apothecial discs. Symbolae Botanicae Upsalienses 32(1): 131-162. 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 Publications, van Herk, C. M. & Aptroot, A. (1996) Epifytische korstmossen komen weer terug. Natura 93: 130-132. Accepted for publication 18 February 1998
