Bacidia albogranulosa Malicek , Palice, Vondrak & Kukwa

licek, Jiri M, alice, Zdenek, Vondrak, Jan, Lubek, Anna & Kukwa, Martin, 2018, Bacidiaalbogranulosa (Ramalinaceae, lichenized Ascomycota), a new sorediate lichen from European old-growth forests, MycoKeys 44, pp. 51-62 : 51

Bacidia albogranulosa Malicek, Palice, Vondrak & Kukwa sp. nov. Fig. 1

Type.

CZECH REPUBLIC. Dolnomoravský úval lowland: Břeclav, Lanžhot, protected area Cahnov, 150 m alt., 48°39'22"N, 16°56'25"E, on bark of Acer campestre , 1 Apr 2014, J. Vondrák (holotype: PRA-Vondrák 11888).

Diagnosis.

The species is characterised by a grey-white hypothallus or very thin thallus covered by groups of white, farinose to granular soredia or by being completely sorediate. Ascomata and pycnidia are unknown. Atranorin is the only secondary metabolite. The species occurs in old-growth forests on bark of broad-leaved trees with high bark pH (> 5).

Etymology.

The name refers to the white rough (granular) soredia that are often present.

Description.

The thallus consists of a hypothallus (i.e. without photobiont cells) or, in some parts, a lichenised and thinly episubstratal thallus (up to 100 μm high), which is smooth or partially areolate, pustulate or granular, grey-white to grey, sorediate. A prothallus is absent or very thin and white. Soredia are not produced in clearly delimited soralia, but dispersed in groups or forming a more or less continuous layer, white or, when fresh, yellowish-white, farinose to granular, simple, (25 –)35– 65 μm in diam., or in consoredia up to 125 μm in diam. Soredia are enclosed by a colourless, more or less compact “wall” without projecting hyphae. The photobiont is trebouxioid, and 5-16 μm in diameter. Ascomata and pycnidia are unknown.

Chemistry.

Atranorin detected by TLC (n=20). Numerous tiny crystals of atranorin visible in water mounts of soredia and thallus in polarised light. Spot reactions: K+ yellow, Pd+ yellowish, C–, KC–, soredia UV+ dull orange, thallus UV– or dull yellowish-white (in 365 nm).

Distribution and ecology.

The new species is reported from the Czech Republic, Poland, Russia (European part of the Caucasus) and Ukraine. It has already been published under a provisional name, Bacidia albogranulosa ined. from the Czech Republic ( Vondrák et al. 2016) and the Ukrainian Carpathians ( Malíček et al. 2018, Vondrák et al. 2018).

Bacidia albogranulosa grows abundantly in old-growth floodplain and scree forests in the Czech Republic and old-growth ash or hornbeam dominated broad-leaved forests in Poland. It rarely occurs in old-growth beech (Ukraine) and mixed forests (Russia). It has usually been found on a dry and coarse bark of broad-leaved trees with a relatively high bark pH (approximately> 5). The most frequent phorophytes are Acer campestre (n=5), A. platanoides (11) and Fagus orientalis / sylvatica (4; overmature or dying trees due to a fungal infection). A few specimens were recorded also on Fraxinus angustifolia (2), F. excelsior (2), Carpinus orientalis (1), Euonymus europaeus (1) and Quercus sp. (2). The species prefers rather shaded trunks and places not directly exposed to rain, similar to many Lepraria species ( Saag et al. 2009).

Alyxoria varia (Pers.) Ertz & Tehler, Bacidia rubella and the non-lichenised fungus Dendrothele acerina (Pers.) P.A. Lemke (on Acer spp.) are the most commonly recorded, co-occurring species. In the Czech Republic, the new species was repeatedly found on weathered bark with the red-listed Gyalecta flotowii Körb. or G. ulmi (Sw.) Zahlbr. It co-occurred also with Acrocordia gemmata (Ach.) A. Massal., Arthothelium spectabile A. Massal., Bacidia fraxinea Lönnr., B. incompta (Borrer) Anzi, Caloplaca flavocitrina (Nyl.) H. Olivier, Gyalecta truncigena (Ach.) Hepp, Hazslinszkya gibberulosa (Ach.) Körb., Inoderma byssaceum (Weigel) Gray, Lecania croatica (Zahlbr.) Kotlov, Lepraria finkii (B. de Lesd.) R. C. Harris, L. vouauxii (Hue) R. C. Harris, Opegrapha vermicellifera (J. Kunze) J. R. Laundon and Pyrenula nitidella ( Flörke ex Schaer.) Müll. Arg.

Phylogeny.

The new species is strongly supported as a distinct clade in the ITS and mtSSU phylogeny (Fig. 2) and belongs to Bacidia s.str. sensu Ekman (2001). According to the ITS data, it is closely related to Bacidia diffracta , B. suffusa and B. polychroa . These four species form a well supported group, characterised by the presence of the pigments Laurocerasi-brown and Polychroa-brown in the apothecia. Bacidia albogranulosa is also related to B. rubella , a species it frequently co-ocurrs with. The only sorediate member of Bacidia s.str., the North American B. sorediata , seems not to be closely related to the new species, based on the ITS and mtSSU sequence data (Fig. 2).

Notes.

Although apothecia and pycnidia are unknown, B. albogranulosa can be recognised in the field by its white-grey hypothallus or very thin thallus covered by groups of white to yellowish-white soredia that often extend across the entire thallus. Ecologically, the species prefers trees with rough and slightly acidic or subneutral bark in old-growth forests.

Bacidia albogranulosa may macroscopically resemble some Lepraria species or poorly developed Phlyctis argena (Ach.) Flot., but it clearly differs by having a non-continuous, locally developed thallus, composed of dispersed granular aggregates that disintegrate into soralia at an early stage and by the lack of a fibrous prothallus. Additionally, atranorin alone is not known from any described Lepraria species ( Saag et al. 2009). Similarly, sorediate European Lecanora species contain other substances in addition to atranorin, such as aliphatic acids, depsides/depsidones or terpenoids and usually form thicker thalli or at least a distinct fibrous hypothallus ( Malíček et al. 2017). A slightly similar appearance is typical for a few other Lecanora species (e.g. L. compallens Herk & Aptroot, L. stanislai Guzow-Krzem., Łubek, Malíček & Kukwa), producing usnic acid and zeorin and forming a yellowish-greenish to greenish-grey sorediate thallus ( Guzow-Krzemińska et al. 2017).

Initial stages of the new species may resemble sterile thalli of Caloplaca substerilis Vondrák, Palice & van den Boom. This taxon lacks atranorin and tends to form thin areolate-squamulose, almost evanescent thalli with occassional sulcate or marginal soralia ( Vondrák et al. 2013). The closely related species B. diffracta produces a similar, finely granular grey thallus and contains atranorin in addition to traces of zeorin. Nevertheless, this species is richly fertile, has larger thalline granules (40-100 μm diam.) and is so far only known from eastern North America ( Ekman 1996). The only presently known sorediate member of Bacidia s.str., B. sorediata , differs in having a better developed, grey-green to dark green thallus, diffuse, rarely confluent soralia and fine soredia. It occurs only in south-eastern North America ( Lendemer et al. 2016) and it is not phylogenetically closely related to B. albogranulosa (Fig. 2).

Additional specimens examined.

CZECH REPUBLIC. Western Bohemia: Český les Mts, Bělá nad Radbůzou, Smolov, protected area Pleš, old-growth mixed forest on scree on E slope, 49°33'02"N, 12°38'21"E, 740-840 m alt., on Acer platanoides , 6 August 2014, J. Vondrák 12865 (PRA). Southern Bohemia: Šumava Mts, Volary, Mt Stožec - Medvědice, a mountain scree deciduous old-growth forest at NNE-facing slope, 48°52'49.5"N, 13°50'03"E, on dry bark of Acer platanoides , 935 m alt., 7 Aug 2014, Z.Palice 17827, Jul. Palicová & K. Palicová (PRA), ibid.: at NE-facing slope, 48.8802°N, 13.8385°E, 900 m alt., on bark of Acer platanoides , 17 Oct 2016, J. Vondrák 17113 & Z.Palice 24362 (PRA). Šumava Mts, Lenora, Mt Zátoňská hora, semi-natural scree deciduous forest at SW-facing slope, just below the top, 48°56'41"N, 13°49'48"E, on bark of Acer platanoides , 1022 m alt., 27 June 2018, J. Malíček & Z.Palice 25133 (PRA). Novohradské hory Mts, Pohorská Ves, nature reserve Žofínský prales, N part of the reserve, old-growth forest at N-NW-facing slope, 48°40'10"N, 14°42'30"E, on bark of Fagus , 765-770 m alt., 18 Aug 2016, Z.Palice 22220 (PRA). Central Bohemia: Křivoklátsko Protected Landscape Area, Skryje, Týřov National Nature Reserve, mixed deciduous forest with shady rocky outcrops in valley of Úpořský potok brook S of Vápenný vrch Hill (424 m), 49°58'09"N, 13°47'43"E, 270 m alt., on bark of Acer platanoides , 11 Aug 2018, J. Malíček 11990 (herb. Malíček). Southern Moravia: distr. Břeclav, Lanžhot, Ranšpurk National Nature Reserve, ca. 48°40'41"N, 16°56'49"E, floodplain old-growth forest, alt. 150 m, on bark of Acer campestre , 10 Oct 2013, J. Malíček 6214 & J. Vondrák (herb. Malíček). Cahnov-Soutok National Nature Reserve, old-growth flood-plained forest 7.5 km SSW of Lanžhot, 48°39'23"N, 16°56'24"E, 150 m alt., on bark of Acer campestre and Fraxinus angustifolia , 1-3 Apr 2014, J. Malíček 6793, 6832, 6863, M.Kukwa 12409, 12434, 12504, 12514, 12515, 12526, Z.Palice 17686 & J. Vondrák 11889, 12051, 12057, (herb. Malíček, PRA, UGDA). Distr. Blansko, Moravský kras Protect. Landscape Area, Vilémovice, Vývěry Punkvy National Nature Reserve, oak-dominated woodlands on SE-facing slope in surrounding of Blansek castle ruin, 49°22'15"N, 16°43'24"E, alt. 425 m, on bark of Acer campestre , 17 Apr 2015, J. Malíček 8013 & V. Lenzová (herb. Malíček).

POLAND. Równina Bielska: Białowieża Primeval Forest, Białowieski National Park, N part of forest section no 286, 52°45'07"N, 23°52'40"E, Tilio - Carpinetum , on Acer platanoides , May 2014, M.Kukwa 12592 (UGDA); ibid.: forest section no 256, Tilio - Carpinetum , on Acer platanoides , May 2014, M.Kukwa 12755 (UGDA); ibid.: Circaeo - Alnetum , on Acer platanoides and bark of fallen Fraxinus excelsior , Aug 2014, M.Kukwa 13135a, 13176 & A. Łubek (KTC, UGDA); ibid.: Tilio - Carpinetum , on Acer platanoides , August and October 2014, M.Kukwa 13292, 14394 & A. Łubek (KTC, UGDA); ibid.: Tilio - Carpinetum , on Acer platanoides , Aug 2015, M.Kukwa 17195, 17584, 17404 & A. Łubek (KTC, UGDA); ibid.: Circaeo - Alnetum , on bark of log ( Fraxinus excelsior ), 24 Aug 2015, M.Kukwa 17446 & A. Łubek (KTC, UGDA).

RUSSIA. Caucasus Mts: Caucasian Biosphere Reserve, Guzeripl’, old-growth deciduous mixed forest ( Quercus robur , Alnus glutinosa , Acer campestre etc.) at right bank of Belaya River, 0.4 km WSW of margin of village, 43°59'20"N, 40°07'30"E, 700 m alt., on bark of Acer campestre , Carpinus orientalis , Fraxinus and Quercus robur , 8-9 June 2016, J. Malíček 9622, 10491, Z.Palice 21600, 21690, 22395, 22622, 22715, 23063, J. Vondrák 14956 & G.Urbanavichus (herb. Malíček, PRA). Guzeripl’, a forested crest between Belaya and Molchepa rivers, just ca. 1 km SSE of the village, well-lit mixed forest at N-wards descending crest, 43°59'12"N, 40°08'30"E, on bark of old Quercus , 935 m alt., 7 June 2016, Z.Palice 22672, 22964 & J. Vondrák 15532 (PRA). Guzeripl’, mixed primeval forest ( Abies nordmanniana , Acer trautvetteri , Fagus orientalis etc.) on a ridge and W-facing slope 3.5 km S of village, 43°57'53"N, 40°07'50"E, 1470 m alt., on bark of Acer platanoides and Fagus orientalis , 14 June 2016, J. Malíček 10802, Z.Palice 22624, 22924, J. Vondrák 15291 & G.Urbanavichus (herb. Malíček, PRA).

UKRAINE. Zakarpattia Oblast Province: Berehovo, Nyzhni Remety: lood-plain forest “Otok” 2.5 km SW of village, close to Mala Borzhava River, 48°14'12"N, 22°48'25"E, 120 m alt., on bark of Acer campestre , 23 Oct 2013, J. Malíček 6463 & J. Vondrák (herb. Malíček). Ibid.: “Otok”, ca. 4 km SW of village, 48°14'00"N, 22°48'20"E, 190 m alt., on bark of Acer campestre , Euonymus europaeus and Fraxinus angustifolia , 3 June 2014, J. Šoun & J. Vondrák 12235, 12206, 12237 (PRA). Khust, Velyka Uhol’ka, old-growth beech predominated forest in valley of Velika Uhol’ka River, ca. 0.7 km NNE of last houses in village, 48°15'02"N, 23°41'47"E, 500 m alt., on bark of old Fagus sylvatica , 13 May 2015, J. Malíček 8166 & Z.Palice 19366 (herb. Malíček, PRA); ibid.: old-growth hornbeam-beech forest, 48°14'43"N, 23°41'39"E, on bark of old Fagus sylvatica , 460 m alt., 19 May 2015, Z.Palice 19392 (PRA).