New records of rare lichenicolous and lichen-forming fungi from volcanic rocks in SW Poland

Records of two lichenicolous and nine lichen-forming fungi found in the southwestern part of Poland are presented. All of the reported species are very rare and they have only a few scattered localities in the country. One of them, Lecanora pannonica, is reported for the second time from Poland. Additionally, the new, contemporary records of Cercidospora macrospora, Rhizocarpon disporum, R. viridiatrum and Stereocaulon pileatum in Lower Silesia were noted. These species were known only from historical collections in the study area. Furthermore, Lecidea fuscoatra has been found a new host for Sagediopsis barbara. All of the localities of recorded species were found on natural outcrops of basalt rocks.


Introduction
The southwestern part of the Poland has the biggest number of basalt rock formations in the country.The rocks in the region are a part of a large Central European petrographic province reaching from Moravian Ostrava and Opavan Silesia, through Opole Silesia, the Sudetes, Upper Lusatia, Saxony and Bohemian Central Uplands to the Rhine Valley and the borders of the Netherlands [1].Within Polish borders the biggest clusters of the rocks are located near Lubań, Zgorzelec, between Lwówek Śląski and Jawor, and between Gryfów Śląski and Świeradów.These clusters are relics of old volcanic fields, of which every group could have had up to a hundred of small volcanoes [2].Basalt volcanism is connected with the youngest tectonic movements (in the Cenozoic Era) in the Sudetes and their vicinity, which were mostly vertical movements.Rocks created in this way exist today mostly as various forms of lava veins -volcanic plugs, flood basalt, volcanic cones and calderas [1].Basalts (volcanic rocks made of plagioclase, pyroxene and olivine) are very hard volcanic rocks with absorptivity and, therefore, they are resistant to repeated processes of freezing and thawing.Because of that they often form denudation monadnocks -inselbergs [3].It is estimated that there are about 300 various basalt rock formations in Lower Silesia [2], most of which were in the past centuries used for mining.Many of these formations are extremely valuable for scientific, didactic, aesthetic and natural reasons and are often protected as landmarks [4].When the rocks decompose due to environmental factors they create fertile soil and decomposed rocks rich in mineral compounds.For that reason many rare plants and plant communities can be found in their vicinity [5][6][7][8][9].Volcanic rocks, including basalt rocks, often foster rare species lichens and lichenicolous fungi because of unique habitat conditions [10][11][12][13][14][15][16].
The current paper includes data on 11 species of lichens and lichenicolous fungi occurring in SW Poland.These species are mostly known from historical collections in the study area and they are currently very rare in the country.All of the presented species are saxicolous and had been discovered on natural outcrops of volcanic rock formations.Additionally, their ecology and distribution in Poland and in Central Europe are briefly characterized.

Material and methods
Material included in the present paper was collected by the author in 2012-2014, on some natural outcrops of volcanic rocks, especially on basalt rocks occurring in SW Poland.
Material was determined using standard methods.Identification of sterile, crustose specimens was supported by TLC analyses of secondary metabolites, according to the methods of Orange et al. [17].The distribution of the taxa examined are given in the ATPOL grid square system [18], modified by Cieśliński and Fałtynowicz [19].The herbarium material is housed in the private herbarium of the author (Hb.Szczepańska).In the text the asterisk ("*") indicates a lichenicolous fungus.

Results and discussion
Buellia badia (Fr.) A. Massal.This species is characterized by subsquamulose to squamulose, brown thallus.It is considered as a saxicolous, however it often grows as a parasite over various lichens, such as Melanelia and Xanthoparmelia species [20].In Poland it is known from the Pojezierza Bałtyckie Lakelands, Nizina Środkowopolska Lowland and Wysoczyzna Podlaska Height [21].In SW Poland it was noted only on the few localities in the Sudety Mts [22][23][24].On the new location, some of the young thalli of B. badia, were growing on the thallus of Xanthoparmelia loxodes (Nyl.)O. Blanco et al.
In Central Europe, B. badia has been found in Austria [25], the Czech Republic [26] and Germany [27].

Caloplaca subpallida H. Magn.
This species belongs to the Caloplaca ferruginea group [28] which includes taxa characterized by whitish to blackish thalli and ferrugineous apothecia.It was reported for the first time, as a new to Poland, in the Sudety Mts, including Przedgórze Sudeckie Foreland and Pogórze Zachodniosudeckie Foothills [16].It grows only on mineralrich, siliceous rocky substrata, especially on the basic and altered ultrabasic rocks, i.e., basalt, greenstone and serpentinite.
In Central Europe, C. subpallida has been found in Austria [25], the Czech Republic [26] and Germany [27].A rare lichenicolous fungus in Poland, reported from only a few localities till now.It was noted in the Pomorze Gdańskie Pomerania and in the XIX century in the Sudety Mts [29].Cercidospora macrospora was recorded in Poland exclusively on the thallus of the Lecanora muralis (Schreb.)Rabenh., however this taxon is also known as growing on different Lecanora species, occurring on siliceous, as well as on calcareous rocks [30].In contrary to other, known from Poland, species -C.epipolytropa (Muss) Arnold, C. macrospora does not show a preference to develop the ascomata in the apothecial discs and they are equally frequent in host thallus and apothecia [31].

Lecanora subaurea Zahlbr.
Lecanora subaurea is listed on the Red list of the lichens in Poland [33], in DD category (data deficient).As a habitat it prefers heavy metal rich lime-free silicate rocks, including iron-rich basalts [27].Due to similar, bright yellow color of the thallus, as well as secondary chemistry and habitat, L. subaurea can be confused with L. epanora (Ach.)Ach.However, in contrary to L. epanora, soredia of L. subaurea arising on the margins of areoles, not on their upper surface.In the country this species has been noted mainly in the southern part of the country, in the Karpaty Zachodnie Mts [21,34].

Lecanora pannonica Szatala
This species was reported only once from northern Poland, in the Pojezierze Iławskie Lackeland and Nizina Staropruska Lowland [39], from three localities.Lecanora pannonica usually grows on anthropogenic substrates [38] and all of its previously known records from Poland, come from old brick made buildings.The new locality of this species in country, for the first time was recorded on natural rocky substrata.This species was observed on vertical surfaces of well lighted basalt rocks, however there were found only sterile thalli.Lecanora pannonica can be confused with Tephromela grumosa (Pers.)Hafellner & Cl.Roux, which is also usually sterile lichen, produce blue-grey, K+ yellow soredia.The features which allow to distinguish L. pannonica from T. grumosa, are distinctly bullate-areolate thallus, discrete, rounded and not confluent soralia as well as chemistry.The specimens were analyzed using TLC method.The thallus contains atranorin (major), roccellic acid (major) and gangaleoidin (trace).

Lecidella scabra (Taylor) Hertel & Leuckert
A lichen species listed on the Red list of the lichens in Poland [33], in NT category (near threatened).Due to similar C+ orange reaction of soredia, L. scabra may be confused with Rinodina aspersa (Borrer) J.R. Laundon.However, R. aspersa differs from L. scabra in secondary chemistry and because of possessing clearly areolate thallus with discrete, not confluent, circular soralia.Lecidella scabra has scattered localities in Poland, situated in the Pojezierza Bałtyckie Lakelands, Wysoczyzna Podlaska Height, Wyżyna Środkowomałopolska Upland and Karpaty Zachodnie Mts [21,34].In SW Poland, L. scabra was noted only in the Sudety Mts [41].Most of the specimens found on the new locality were sterile and in order to proper identification of the specimens, TLC analysis was performed.Thallus of the species contains atranorin (major) and xanthones: thuringione (minor) and arthothelin (major).Additionally there was found some unidentified substance (Rf class in solvent C -35, spot color after acid and heating -colorless, UV after heating -bright yellowish-green).

Rhizocarpon viridiatrum (Wulfen) Körb.
Rhizocarpon viridiatrum is considered as a rare species in Poland and is listed on the Red list of the lichens in Poland [33], in VU category (vulnerable).It was recorded in the Pojezierza Bałtyckie Lakelands and Karpaty Zachodnie Mts [21,34].In SW Poland R. viridiatrum was noted only in historical papers, in the Sudety Mts [22,23,45,46].Young thalli of this species are known as initially parasitic on other saxicolous, crustose lichens, especially on Aspicilia caesiocinerea (Malbr.)Arnold [38].On the new locality it was found growing on the Aspicilia cinerea (L.) Körb.thallus, in light, exposed but rather warm places.

Stereocaulon pileatum Ach.
This is a mountain species, listed on the Red list of the lichens in Poland [33], in EN category (endangered).It was noted only in the southern part of the country, on the few localities, in the Karpaty Zachodnie Mts [21,34] and Sudety Mts [23,45,47,48].This species is characterized by wart-like phyllocladia and distinctly globose soralia, located at the ends of small pseudopodetia.The appearance and position of soralia distinguishes this species from the other taxon with small thallus -S.nanodes Tuck.Till now, S. pileatum has been known as growing only on sandstone and granite rocks and this is the first record of this species noted on the basalts.
In Central Europe, S. pileatum has been found in Austria [25], the Czech Republic [26] and Germany [27].[29].It is known as a parasite restricted to Porpidia rugosa (Taylor) Coppins & Fryday [49], however, some others lichens, like Lecanora and Lecidea genera, are mentioned as a hosts of this taxon [50].On the new localities S. barbara was noted on the thallus of the Lecidea fuscoatra (L.) Ach.This species differs from similar S. aquatica (Stein) Triebel mainly in the larger size of perithecia and ascospores.
In Central Europe, S. barbara has been found in Austria [51] and the Czech Republic [32].

Specimens examined. Ea
In Central Europe, T. grumosa has been found in Austria [25], the Czech Republic [26] and Germany [27].