Note on Caloplaca soralifera ( Teloschistaceae , lichenized Ascomycetes ) in Poland

In accordance with the recent development of taxonomic studies on Caloplaca global and local knowledge of the genus increased rapidly [1-5]. Hundreds of species received modern circumscription and great number of new ones were described in the recent decade [6-8]. The ongoing revision of the Caloplaca genus in Poland indicated several species new to the country [9,10]. Further study resulted in discovery of C. soralifera Vondrák & Hrouzek that is here reported for the first time from the area of Poland. Caloplaca soralifera is most recently described species and belongs to the group of sorediate representatives of Caloplaca lacking anthraquinones in the thallus [11]. When fertile, the species is distinctive due to zeorine, orange colored apothecia. However, C. soralifera also occurs in a sterile form that is inconspicuous and probably often overlooked. Caloplaca soralifera was mainly reported from man-made substrata so far, e.g. concrete and mortar in rural/urbanized areas. The distribution range of this species is expanding [11]. The species is characterized in detail and a taxonomic discussion explaining the differences between most similar species is provided in the paper; its distribution and ecology is also discussed. Material and methods


Introduction
In accordance with the recent development of taxonomic studies on Caloplaca global and local knowledge of the genus increased rapidly [1][2][3][4][5].Hundreds of species received modern circumscription and great number of new ones were described in the recent decade [6][7][8].The ongoing revision of the Caloplaca genus in Poland indicated several species new to the country [9,10].Further study resulted in discovery of C. soralifera Vondrák & Hrouzek that is here reported for the first time from the area of Poland.
Caloplaca soralifera is most recently described species and belongs to the group of sorediate representatives of Caloplaca lacking anthraquinones in the thallus [11].When fertile, the species is distinctive due to zeorine, orange colored apothecia.However, C. soralifera also occurs in a sterile form that is inconspicuous and probably often overlooked.Caloplaca soralifera was mainly reported from man-made substrata so far, e.g.concrete and mortar in rural/urbanized areas.The distribution range of this species is expanding [11].
The species is characterized in detail and a taxonomic discussion explaining the differences between most similar species is provided in the paper; its distribution and ecology is also discussed.
Morphological characters were examined on dry material using a dissecting microscope.Anatomical characters were measured on hand-cut sections and squash preparations mounted in water.The structure of paraphyses and cortical tissues were observed in 25% KOH (K).The granulation of tissues was observed in polarized light; pol+/pol− means that the granules reflect or do not reflect polarized light.The solubility of granules and/or crystals was tested with K and 65% nitric acid (N).K and N were also used for spot test reactions.The terminology for tissues follows [2,12,13].

Distribution and ecology
The species was recorded on scattered sites both in the area of northern and southern Poland (Fig. 1).It is perhaps much more widespread in the country but undercollected.
Until now Caloplaca soralifera has been reported from the following European countries: Austria, Bulgaria, the Czech Republic, Germany, Slovakia, Romania [11], Britain [14] and Ukraine [15].It has been also recorded from USA [4].
The species usually grows on artificial substrata (e.g., concrete, mortar, asphalt, nutrient-rich siliceous stones), and only rarely on natural ones (e.g., calcareous or base-rich siliceous rocks) [11].In Poland the species was found on both considered substrate types -mainly on concrete and less frequently on calcareous stones.

Discussion
Caloplaca soralifera is characterized by an areolate, grey, often whitish pruinose thallus.The apothecia are zeorine with proper and thalline margins present, orange and grey respectively.The dark violet-grey soredia produced on the margin of thalline areoles and presence of thalline cortex are most diagnostic characters for the species.
Caloplaca soralifera is closely related with C. xerica [11].The latter species, however, differs in having esorediate, isidiate thallus and quite different ecology -it occurs mainly in xerothermic habitats and occupies base-rich siliceous rocks.Caloplaca chlorina (Flot.)H. Olivier is another similar taxon but it is distinguished by a typical lecanorine apothecia, rarely pruinose thallus and ecology; the species occurs mainly on siliceous stones and rocks (see also [11]).Concerning both habit of thallus and apothecia as well as ecology C. soralifera seems related to C. albolutescens.In case of the latter species lack of thalline cortex is a helpful, distinguishing character.Moreover, the whole thallus of C. albolutescens is filled by crystals on a cross section (pol+, insoluble in K, soluble in N) and the structure of the algal layer is almost invisible, whereas, in C. soralifera crystals obscure only the cortex and the structure of algal layer is clearly visible, with distinct isodiametric fungal cells intermixed with algae.What is more, the thallus of C. albolutescens is white and tartareous, instead of grey and compact in C. soralifera.When sterile, C. soralifera could be confused most likely with C. concreticola.Beside morphological similarities both taxa occur on the same man-made substrata such as concrete.The reaction with K of the thallus cortex is a main character distinguishing those species; C. soralifera reacts K+ violet, whereas C. concreticola does not react with K.When fertile, C. concreticola is easily distinguished from C. soralifera due to its brownish apothecia [16].Finally, C. pratensis is somewhat similar to C. soralifera in the thallus appearance.The former species differs in soredia mainly present on the upper surface of the areoles and brownish apothecia.Caloplaca pratensis, however, is known only from North America so far [4].
The studied material from Poland was often misidentified as C. teicholyta.The latter species is in fact quite different than C. soralifera.It has thick thallus, roundish in outline, and lobate at its margin.The areoles in the center of thallus are dissolved into granules, isidia and soredia giving the surface scruffy-granular appearance.Moreover, C. teicholyta rarely forms apothecia; they are distinctly reddish when present.