Opuscula Philolichenum, 12:180-197. 2013. *pdf effectively published online 25November2013 via (http://sweetgum.nybg.org/philolichenum/) Lichenicolous fungi and some allied lichens from the Canadian Arctic 1 MIKHAIL P. ZHURBENKO ABSTRACT. – Forty species of lichenicolous fungi and two allied lichens are reported from the Canadian Arctic, 30 being new to this area. Four species are described as new to science: Lichenochora arctica (on Candelariella canadensis and Rinodina terrestris), L. rinodinae (on Rinodina mniaraea, R. roscida and R. turfacea), Llimoniella catapyrenii (on Catapyrenium cinereum and Catapyrenium sp.) and Opegrapha buelliae (on Buellia insignis). Arthonia almquistii, Cercidospora ochrolechiae, Dactylospora rhyparizae, Didymellopsis pulposi, Lichenochora lepidiotae, Skyttea dacampiae, Stigmidium mitchellii and Zwackhiomyces macrosporus are reported new to North America; Arthonia digitatae, Minutoexcipula mariana and Skyttea dacampiae are reported new to the Arctic; Arthonia digitatae, A. excentrica, C. verrucosaria, Lichenoconium pyxidatae, Merismatium heterophractum, Minutoexcipula mariana, Pseudopyrenidium tartaricola and Zwackhiomyces berengerianus are reported new to Canada. Candelariella, Lecidella, Megalaria and Rinodina are reported as new host genera for Arthonia almquistii, Megalaria for Cercidospora punctillata and Dactylospora deminuta, Protopannaria for Lichenochora lepidiotae, Lecidella for Skyttea dacampiae, Fuscopannaria for Stigmidium mitchellii, Sticta for Stigmidium peltideae and Fuscopannaria for Zwackhiomyces macrosporus. KEYWORDS. – biogeography, taxonomy, new species, parasites. INTRODUCTION To date 46 species of lichenicolous fungi have been reported from the Canadian Arctic, which represents about 13% of the total known species diversity of this fungal group in the entire Arctic Region (Diederich & Zhurbenko 2001, Kristinsson et al. 2010, Zhurbenko 2012). While processing geobotanical lichen collections from the Canadian Arctic (Zhurbenko et al. 2006) a number of lichenicolous fungi were detected. Results of their identification are presented in this paper, which enlarges to 75 the number of lichenicolous fungus species known from this part of the Arctic. Additionally, four species new to science are described, eight are reported new to North America and three new to the Arctic. Taxonomical observations on some insufficiently known species are provided. MATERIALS AND METHODS This study is based on 118 specimens, examined with Zeiss microscopes Stemi 2000−CS and Axio Imager A1 equipped with Nomarski differential interference contrast optics. Microscopical examination was done in water, 10% KOH (K), Lugol’s iodine, directly (I) or after a KOH pre-treatment (K/I), phloxin, cotton blue or brilliant cresyl blue (BCr). The length, breadth and length/breadth ratio (l/b) of asci, ascospores and conidia are given (where possible) as: (min−){X−SD}−{X+SD}(−max), where min and max are the extreme values, X the arithmetic mean and SD the corresponding standard deviation. Measurements were taken from water mounts, unless otherwise indicated. Nomenclature of the host lichens 1 MIKHAIL P. ZHURBENKO – Laboratory of the Systematics and Geography of Fungi, Komarov Botanical Institute Russian Academy of Sciences, Professor Popov 2, St.-Petersburg, 197376, Russia. – e-mail: [email protected] 180 follows Esslinger (2012). The classification of the Ascomycota follows Lumbsch and Huhndorf (2007). Examined specimens are housed in the mycological herbarium of the V.L. Komarov Botanical Institute in St.-Petersburg (LE-Fungi). The majority of the specimens cited herein were collected at two localities: 1) abbreviated ERI = CANADA. NORTHWEST TERRITORIES: Ellef Ringnes Island, Isachsen Bay, 78°47−48'N, 103°32−36'W, alt. 20−70 m, arctic desert, and 2) abbreviated PPI = CANADA. NORTHWEST TERRITORIES: Prince Patrick Island, Mould Bay, 76°13−14'N, 119°18−20'W, alt. 10−30 m, transition between arctic tundra and arctic desert. Additional abbreviations used in the text below are: NM – Nadezhda V. Matveeva; DW – Donald A. Walker; ap. − apothecia; th. − thallus/thalli. Lichenicolous lichens are designated by a superscript letter L (“L”) preceding the name of the taxon at the beginning of each entry in the text. THE TAXA Arthonia almquistii Vain. CHARACTERIZATION OF THE MATERIAL. – Ascomata black, more or less matt, epruinose, with minutely rough surface, rounded or elongated in surface view, often somewhat flattened at the top, 75−600 µm across, superficial, dispersed to aggregated, sometimes confluent (then up to 2 mm across). Exciple indistinct. Epithecium medium to dark olive brown, 10−15 µm tall, K−. Hymenium pale olive brown, 40−50 µm tall, I+ red, K/I+ blue. Hypothecium medium to dark olive brown, 40−80 µm tall. Apices of paraphysoids sometimes with dark caps, usually somewhat swollen, 2.5−4.5 µm wide. Asci broadly clavate, ca. 33−57 × 16−20 µm, with K/I+ blue apical ring, 8-spored. Ascospores narrowly obovate to clavate/skittle-shaped, (11.0−)12.9−15.5(−18.0) × (4.0−)4.7−5.5(−6.0) µm, l/b = (2.2−)2.5−3.1(−3.6) (n = 111, in water or I), 1-septate (a few non-septate evidently immature ascospores were also observed), not or slightly constricted at the septum, hyaline, smooth-walled, with halo 0.5−1.5 µm thick and many small guttules clearly seen in K. Pathogenicity not observed. NOTES. – The examined material fits well the description of Arthonia almquistii (Coppins & Aptroot 2009: 157), but is unusual with respect to its host selection. So far the species has almost exclusively been known from saxicolous species of several unrelated genera (Amygdalaria, Farnoldia, Koerberiella, Porpidia and Trapelia; Hafellner & Türk 1995, Santesson et al. 2004, Triebel 1989). However, it has also been reported from the terricolous crustose lichen Bilimbia sabuletorum (Kukwa & Flakus 2009) and probably colonizes a wide range of Lecanoromycetes. Here the range of hosts for A. almquistii is expanded considerably to include the genera Candelariella, Lecidella, Megalaria and Rinodina. This is also the first report of the species from North America. Specimens examined. – ERI: 29.vii.2005, on thalli of intimately mixed Candelariella sp., Lecidella wulfenii, Megalaria jemtlandica and Rinodina terrestris growing on soil, DW (LE 260636); 22.vii.2005, on L. wulfenii, NM (LE 260836, LE 260716); 22.vii.2005, on M. jemtlandica, NM (LE 260616, LE 260816); on M. jemtlandica, 23.vii.2005, NM (LE 260726). Arthonia digitatae Hafellner CHARACTERIZATION OF THE MATERIAL. – Apothecia 50−250 µm diam., black, aggregated to confluent. Epihymenium medium brown, hymenium pale smoke grey, hypothecium medium brown, all parts K−. Hymenial gel I+ blood red, K/I+ blue. Ascospores hyaline, 1-septate, with wider upper cell, not constricted at the septum, (9.5−)10−11.5(−12.5) × 4−4.5(−5) µm, l/b = (2.0−)2.3−2.7(−3.1) (n = 35, in water or I), occasionally with indistinct halo. NOTES. – Here Cladonia coccifera is reported as a new host species for Arthonia digitata. This report represents the first one for Canada and the Arctic. Specimen examined. – ERI: 25.vii.2005, on Cladonia coccifera (tops of more or less moribund cups), NM (LE 260706). Arthonia excentrica Th. Fr. NOTES. – In the specimens cited below the ascospores are rarely non-septate, occasionally with a halo approximately 1 µm thick, and measure (10.5−)11.5−14.5(−16) × (4.5−)5−6(−6.5) µm, l/b = (1.8−)2.2−2.8(−3.2) (n = 36). This is the first report of Arthonia excentrica from Canada. Specimens examined (both on thalli of Lepraria gelida). – ERI: 23.vii.2005, NM (LE 260875). − PPI: 21.vii.2004, DW (LE 260695). 181 Arthonia peltigerina (Almq.) H. Olivier NOTES. – Arthonia peltigerina is widely distributed in the Holarctic and is also known from Chile in South America (Alstrup & Ahti 2007, Etayo & Sancho 2008) where it grows on Peltigera and Solorina species. The taxon was previously reported from Canada by Alstrup (2004) and Zhurbenko (2009b). Specimens examined (all on upper and lower surfaces of lobe margins of Peltigera spp.). – ERI: 24.vii.2005, on P. canina, NM (LE 260885); 20.vii.2005, on P. didactyla, NM (LE 260865); 20.vii.2005, on P. leucophlebia, NM (LE 260895a); 22.vii.2005, on P. cf. rufescens, NM (LE 260845). Cercidospora ochrolechiae Zhurb. NOTES. – This recently described species was previously known only from the Russian Arctic, where it is rather common (Zhurbenko 2010b). This is the first report of Cercidospora ochrolechiae from North America. Specimen examined. – ERI: 20.vii.2005, on Ochrolechia inaequatula (th., occasionally ap.), NM (LE 260489). Cercidospora punctillata (Nyl.) R. Sant. s.l. NOTES. – The species is known from a wide range of host genera (Solorina being the one of its type) and might be heterogeneous. One of the collections cited below (LE 260882) represents the first report of this species from the genus Megalaria. These records are the first report for Cercidospora punctillata, albeit in a broad sense, from North America, except Greenland where it was reported, for example, by Alstrup and Hawksworth (1990). Specimens examined. – ERI: 23.vii.2005, on Megalaria jemtlandica (th.), NM (LE 260882); 20.vii.2005, on Protopannaria pezizoides (moribund bleached th. and/or ap.), NM (LE 260782); 24.vii.2005, NM (LE 260635, LE 260752); 28.vii.2005, NM (LE 260662); 20.vii.2005, on an unidentified terricolous lichen (th.), NM (LE 260812). Cercidospora stereocaulorum (Arnold) Hafellner NOTES. – This taxon grows on Stereocaulon species and is widely distributed in the Holarctic and also