Revisions of British and Irish Lichens Volume 17 September 2021 Baeomycetales: Xylographaceae Cover image: Lithographa tesserata, Glacier Bay, Alaska. Image copyright Måns Svensson, Museum of Evolution, Uppsala University. Revisions of British and Irish Lichens is a free-to-access serial publication under the auspices of the British Lichen Society, that charts changes in our understanding of the lichens and lichenicolous fungi of Great Britain and Ireland. Each volume will be devoted to a particular family (or group of families), and will include descriptions, keys, habitat and distribution data for all the species included. The maps are based on information from the BLS Lichen Database, that also includes data from the historical Mapping Scheme and the Lichen Ireland database. The choice of subject for each volume will depend on the extent of changes in classification for the families concerned, and the number of newly recognized species since previous treatments. To date, accounts of lichens from our region have been published in book form. However, the time taken to compile new printed editions of the entire lichen biota of Britain and Ireland is extensive, and many parts are out-of-date even as they are published. Issuing updates as a serial electronic publication means that important changes in understanding of our lichens can be made available with a shorter delay. The accounts may also be compiled at intervals into complete printed accounts, as new editions of the Lichens of Great Britain and Ireland. Editorial Board Dr P.F. Cannon (Department of Taxonomy & Biodiversity, Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK). Dr A. Aptroot (Laboratório de Botânica/Liquenologia, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Avenida Costa e Silva s/n, Bairro Universitário, CEP 79070-900, Campo Grande, MS, Brazil) Dr B.J. Coppins (Royal Botanic Garden, Inverleith Row, Edinburgh EH3 5LR, UK) Mr A. Orange (Department of Natural Sciences, National Museum of Wales, Cardiff CF10 3NP, UK) Mr N.A. Sanderson (3 Green Close, Woodlands, Southampton, Hampshire SO40 7HU, UK) Dr J.A. Simkin (School of Natural and Environmental Science, Newcastle University, Newcastle upon Tyne NE1 7RU, UK) Dr R. Yahr (Royal Botanic Garden, Inverleith Row, Edinburgh EH3 5LR, UK) Downloads can be obtained from the British Lichen Society website at https://www.britishlichensociety.org.uk/content/lgbi3 Made available under Creative Commons Licence CC BY-SA ISSN 2634-7768 © British Lichen Society, 1 September 2021 Revisions of British and Irish Lichens vol. 17 Baeomycetales: Xylographaceae including the genera Lambiella, Lithographa, Ptychographa and Xylographa by Paul Cannon Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK; email [email protected] Alan Fryday Herbarium, Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA Toby Spribille Department of Biological Sciences, CW405, University of Alberta, Edmonton, Alberta T6G 2R3, Canada Brian Coppins Royal Botanic Garden, Inverleith Row, Edinburgh EH3 5LR, UK Jan Vondrák Institute of Botany of the Czech Academy of Sciences, Průhonice CZ‐252 43, Czech Republic Neil Sanderson 3 Green Close, Woodlands, Southampton, Hampshire, SO40 7HU, UK Janet Simkin School of Natural and Environmental Science, Newcastle University, Newcastle upon Tyne NE1 7RU, UK This publication can be cited as: Cannon, P., Fryday, A., Spribille, T., Coppins, B., Vondrák, J., Sanderson, N. & Simkin, J. (2021). Baeomycetales: Xylographaceae, including the genera Lambiella, Lithographa, Ptychographa and Xylographa. Revisions of British and Irish Lichens 17: 1-11. 2 XYLOGRAPHACEAE Tuck. (1888) Thallus crustose, effuse, areolate, granular or of goniocysts, often immersed within the substratum. Photobiont chlorococcoid, sometimes lichenicolous but with an independent thallus. Isidia or soralia present in some species. Ascomata roundish or angular to linear, usually ± innate, sometimes strongly melanized, with an exposed or nearly concealed disc, sometimes contorted, gyrose or umbonate. Thalline margin absent. True exciple of interwoven hyphae, pigmented, sometimes friable and carbonaceous, not amyloid. Hymenium usually hemiamyloid, rarely euamyloid, sometimes with brown pigmentation. Hamathecium of unbranched or branched paraphyses, sometimes moniliform above, the apices sometimes swollen and pigmented. Asci clavate to cylindrical, Lambiella-type or Trapelia-type. Ascospores aseptate, often thin-walled, colourless, broadly to narrowly ellipsoidal. Conidiomata pycnidia, globose, part-immersed to superficial. Conidia filiform and curved or bacillar. Four genera are included (Lücking et al. 2016), all of which occur in Great Britain and Ireland. The family occupies a clade sister to the Trapeliaceae (Resl et al. 2015) within the Baeomycetales (Kraichak et al. 2018, Lücking 2019). The type species of Elixia (Elixiaceae) was once placed within Ptychographa but has a different ascus structure (Lumbsch 1997) with blueing in Lugol’s iodine restricted to a narrow band at the base of the tholus, and is now assigned to the Umbilicariales. Literature Kraichak et al. (2018), Lücking (2019), Lücking et al. (2016), Lumbsch (1997), Resl et al. (2015), Spribille et al. (2014). 1 Apothecia rounded, the disc often gyrose or umbonate, sunken below the level of the exciple ...................................................................................................................................................Lambiella Apothecia elliptical to linear in outline .................................................................................................... 2 2(1) Outer surface of apothecium pale brown; paraphyses unbranched or sparingly branched ..... Xylographa Outer surface of apothecium black and brittle; paraphyses various ........................................................ 3 3(2) On rock; thallus well-developed, K+ yellow→red (norstictic acid) ......................................Lithographa On wood; thallus of indistinct granules, K– ....................................................................... Ptychographa LAMBIELLA Hertel (1984) Thallus (where present) effuse, continuous or areolate, sometimes ± papillate or tuberculate, occasionally endosubstratal and then inconspicuous, pale to dark grey, brownish or black, matt, closely adnate to the substratum, sometimes minutely isidiate or granular; areoles convex to strongly bullate; prothallus mostly undifferentiated, or black, effuse, marginal and/or visible between the areoles; medulla I– or I+ violet (in non-British species). Photobiont chlorococcoid, some species lichenicolous but retaining an independent thallus. Punctiform soralia present in one species, with dark brown soredia. Apothecia lecideine, roundish to lobate or elongate, sessile to basally constricted or rarely innate; disc black, flat, often gyrose; true exciple prominent, persistent, sometimes flexuose, 3 usually distinctly elevated above the level of the disc. Epithecium greenish to golden or dark brown. Hymenium colourless or green-tinged below. Hamathecium of branched and anastomosed paraphyses, usually moniliform above. Hypothecium usually brownish. Asci broadly clavate, mostly Lambiella-type, with a KI+ blue tholus with a funnel-shaped central unstained region, and a small obconical apical KI+ blue dome. Ascospores broadly ellipsoidal to ovoid, sometimes thin-walled and easily misshapen, colourless but with occasional spores discoloured brownish. Conidiomata pycnidia, brown to black, sessile or partly immersed. Conidia bacillar, aseptate, colourless. Ecology: on bark or siliceous rock, some species lichenicolous or overgrowing crustose lichens or mosses. Introduced by Hertel (1984) for the southern circum-polar species Lambiella psephota, (subsequently reported from the Arctic), but soon after placed into synonymy with Rimularia (Trapeliaceae). The genus was re-established by Spribille et al. (2014) and Resl et al. (2015) with molecular support. Important morphological features include the apothecia surrounded by a rim-like exciple and the branched and anastomosing paraphyses that are moniliform above. Rimularia differs by asci with a narrow central non-staining tube within the KI+ blue tholus (apical dome) in addition to the features described for Lambiella (the difference is subtle and intermediates occur; see Hertel & Rambold 1990, Lumbsch 1997), and thalli that lack depsidones (Resl et al. 2015). Lambiella species are also included in the key to Rimularia (q.v.). Literature Giavarini & David (2009), Hertel (1984), Hertel & Rambold (1990), Lumbsch (1997), Resl et al. (2015), Spribille et al. (2014). 1 Discrete punctiform soredia present; on bark ............................................................................ fuscosora Soredia absent; on rocks, bryophytes or other lichens ............................................................................. 2 2(1) Thallus C+ red (gyrophoric acid) or C–; thallus surface finely isidioid; lichenicolous ................. furvella Thallus C– (gyrophoric acid absent); thallus areolate or granular-areolate .............................................. 3 3(2) Thallus K+ yellow→red (norstictic acid) ................................................................................................ 4 Thallus K+ yellow or K– (norstictic acid absent) .................................................................................... 6 4(3) Thallus dark grey; apothecia usually contorted, slit-like ..........................................................