Is a remarkable species – Caloplaca flavescens (lichenized fungi) – new to the Polish lichen biota?

: Is a remarkable species – Caloplaca flavescens (lichenized fungi) – new to the Polish lichen biota ? acta Mycol. 43(2

introDuction Caloplaca flavescens (Huds.) J.r. Laundon is a member of the lobate species of the genus Caloplaca and it is included in the subgenus Gasparrinia tornab. defined as having lobate thallus and containing anthraquinones (giving K+ violet-red reaction) and it is included in the group C. aurantia characterized by lemon-shape ascospores. the species is distinctive due to narrow, convex marginal lobes that are separated by furrows and gray cortical crystals that are prominent in polarized light. it is calcicolous lichen occurring most often on limestone outcrops. the nomenclature and taxonomic position of the species was established by Laundon (1984). clauzade and roux (1985) contributed significantly to the understanding of the species and provided its circumscription and excellent demonstrative illustrations. the species was detailed treated and widely discussed in the most recent revision of C. aurantia group in the czech republic by Šoun (2005) and in the monograph of lobate species of Caloplaca with a special reference to C. saxicola group in Europe by Gaya (2005).
the taxon was noted for the first time from Poland by nowak and tobolewski (1975)  such material was found at KraM herbarium. under the species name Caloplaca flavescens the taxon was recognized for the first time during lichenological studies of the Krakowsko-częstochowska upland by J. nowak in 1986 and of the Beskid Sądecki range in the Polish western carpathians by L. Śliwa in 1992. the species was collected from single localities and the specimens were housed in KraM and Kra herbaria respectively. the records, however, have never been published as they were considered by the collectors as uncertain. the determination was confirmed by c. wetmore in 1997. while visiting KraM herbarium at the same time wetmore revised the material of C. aurantia group and majority of the collection was re-identified as C. flavescens. Moreover, during a joint field trips with L. Śliwa to different parts of southern Poland he collected the species himself and the material is housed at Min herbarium. Based on the above collections the species was included in the checklists of the western carpathians (Bielczyk 2003;Bielczyk et. al. 2004) and subsequently indicated in the recent Polish checklist (Fałtynowicz 2003). no information concerning collecting sites were provided in any of the publications. During the recent study of calcicolous species of Caloplaca in the Polish western carpathians by K. wilk all material was revised and some new localities of C. flavescens were found (wilk 2008). the species appeared much easier determinable but based primarily on some anatomical characters and more frequent than it was considered before. the main purpose of this account is to make the status of C. flavescens in Poland clear and to encourage lichenologists to pay special attention to this remarkable species.
For light microscopy, free-hand sections were made with a razor blade and mounted in water. tissue and ascospore measurements were made in water. Measurements are rounded to the nearest 0.5 microns. Granulation of tissues was observed in polarized light. the solubility of granules or/and crystals was tested with ca 25% KoH (K) and 65% nitric acid (n); these last two reagent tests were always carried out on separate cross sections. Spot test reactions of thalli, apothecial margins and discs were made with the same reagents.
DiScuSSion. Caloplaca flavescens can be rather easily distinguished by long, narrow and convex marginal lobes and spores that are lemon-shaped. Moreover, the thallus cortex of the species is obscured by wide layer of grey crystals (Fig. 2a) that are prominent in polarized light (Fig. 3a). Due to these character it is rather unlikely to be mistaken with any other Caloplaca member. the species is mostly related to C. aurantia (Fig. 1B). the latter species, however, lacks crystals in the thallus cortex (Figs 2B, 3B). the thalline lobes of C. aurantia are flat and distinctly broader at the ends and closely attached one to the other. Moreover, the species is lighter and often zonated in colour. Both species are widely discussed by Šoun (2005) and Gaya (2005).
representatives of C. saxicola complex have much smaller thallus with considerable shorter lobes that are often pruinose or scabrid. the members of the group have also ellipsoid spores. Most of species of the group differ also in habitat preferences.
another similar taxon is C. thallinicola (wedd.) Du rietz. it differs from C. flavescens by very elongated lobes, deeper furrows between lobes and cortical crystals clustered into spherical, separated groups (see clauzade & roux 1985). Most of all, however, the species differs in ecology. it occupies maritime acid and calcareous rocks.
remarkS. as a result of C. flavescens delimitation a distribution of C. aurantia in Poland is in need of urgent revision. the species is most likely more rare than indicated in bibliographic sources. well as in Scandinavian countries (norway and Sweden: Santesson et al. 2004). it was also reported from near and Middle East (israel: Kondratyuk et al. 1996b;turkey: John 1996) and northern africa (Egypt: Seaward and Sipman 2006;Morocco: Egea 1996;tunisia: Seaward 1996). according to Šoun (2005) it was also recorded in canary islands, azores and European part of russia.  30 Sept. 1986, J. Nowak (KraM-L 30454).