NEW DATA ON THE DISTRIBUTION OF RANUNCULUS POLYPHYLLUS WALDST . & KIT . EX WILLD . IN SERBIA

During our field studies of saline meadows, salt marshes and swampy flora carried out near the Bački Monoštor and Melenci villages (Vojvodina, Serbia) several specimens of the genus Ranunculus L. (Ranunculaceae) were found and identified as Ranunculus polyphyllus Waldst. & Kit. ex Willd. Apart from two records from the beginning of the last century, the appearance of this rare species has been uncertain in the flora of Serbia. We confirmed its presence at one known and two new localities in salt marsh and aquatic floating communities. Also, this is the first herbarium evidence of the presence of this species in Serbia.


INTRODUCTION
There are approximately 600 species of the genus Ranunculus L. distributed worldwide except in lowland tropics (Tamura, 1995;Whittemore, 1997).The distribution pattern shows high morphological diversity and frequent polyploidy (Hoffmann et al., 2010).According to Gajić et al. (1992) there are 51 species of Ranunculus in Serbia divided into two subgenera and ten sections.During our floristic studies of saline meadows, salt marshes and swamps carried out in Bačka and Banat (Vojvodina, Serbia) we found Ranunculus polyphyllus Waldst.& Kit.ex Willd.at three locations (Map 1).Although, there are some old literature records about its presence in Serbia (Prodán, 1914;1915;Kovács, 1929; both authors subsequently cited by Budak, 1998), this species remains neglected in the "Flora of Serbia" (Gajić, 1970;Gajić et al., 1992).
We observed it at one known and two new localities.

MATERIALS AND METHODS
Herbarium material is deposited in the Natural History Museum in Belgrade (BEO) (Holmgren et al. 1990; http://sciweb.nybg.org/science2/IndexHerbariorum.asp) and the Institute for Nature Conservation of Vojvodina (HIPNS).The taxon description follows Tutin andAkeroyd (1993), Ovchinnikov (1937;1970) and Waldstein and Kitaibel (1802) with some amendments based on individuals collected by the authors.Distribution of the taxon in Serbia is given on a map with 10 × 10 km 2 UTM grid system (Lampinen, 2001).
General distribution -This is a Eurosiberian lowland species distributed in the Eurasian forest-steppe zone from northern Kazakhstan and the southern part of western Siberia to the Pannonian plain (Holub, 1999;Luferov and Borodina-Grabovskaya, 2001).The record from the ecologically different and geographically isolated mountain site in eastern Anatolia (Turkey) is likely to be doubtful (Sorger and Buchner, 1983).It was described from Hungary and recorded in Slovakia (Futák, 1982;Holub, 1999), Romania (Nyárády, 1953;Ciocǎrlan, 2009), Ukraine, Russia and Kazakhstan (Ovchinnikov 1937;1970;Luferov and Borodina-Grabovskaya, 2001).Populations in Serbia are on the southwestern border of the species range.The closest populations are situated in southern Hungary (Szujkó-Lacza et al. 1993;Jalas and Suominen, 1989).
General data -rare in Bačka, on swampy areas and salt marshes near the Danube and Tisa rivers (Budak, 1998).According to Slavnić (1956), vegetation of the shallows beside water shores on mineral soils in Vojvodina is provisionally included in ass.Ranunculetum aquatilis-polyphylli Soó 1933, and fragmentary developed, without R. polyphyllus (however he made relevés in August when this species has already completed its life cycle).In addition, Prodán (1914) mentioned this species with R. aquatilis L. There is one sheet with two individuals of R. polyphyllus in the herbarium collection of G. Prodán in the Sombor City Museum, without any location data (Boža et al., 2007).
The reconfirmed and new records from the vicinity of the Bački Monoštor and Melenci villages have been reported as abstracts (Perić et al., 2009;Panjković et al., 2010).
Taxonomic position -Mostly treated as a member of section Xanthobatrachium (Prantl) L. Benson (Ovchinnikov, 1937;Nyárády, 1953;Popov, 1957;Tutin et Akeroyd, 1993;Tzvelev, 1994), R. polyphyllus has been recently included in the separate section Polyphyllus (Tzvelev) Luferov-Grabovsk.(syn.sect.Xantobatrachium subsect.Polyphylli Tzvel.), together with the arcto-alpine circumpolar species R. pygmaeus Wahlenb.The main diagnostic characteristics of the section Polyphyllus are usually numerous whorled cauline leaves and the submerged leaves are often with elongated and filamentous peduncles.In addition, all members of section Xanthobatrachium (Prantl) L. Benson are perennial, while R. polyphyllus is annual (erroneously reported as perennial by some authors) (Luferov and Borodina-Grabovskaya, 2001).This classification proposal is not supported by recent nrITS phylogeny data (Hörandl et al., 2005).According to this data, section Xanthobatrachium corresponds to the subclade IV of large core clades (comprising a total of 19 subclades) inside the genus Ranunculus, and it is closely related to a phylogenetically unresolved branch with polymorphic R. sceleratus (in the early stage of development R. polyphyllus can be confused with R. sceleratus).On the other hand, R. pygmaeus, as a second member of "section Polyphyllus" is located within subclade I comprising arctic and high alpine northern hemisphere species and corresponds to the section Ranunculus (sensu Tamura, 1995).In addition, R. polyphyllus was not included in the materials used in the study of Hörandl et al. (2005), so its phylogenetic and taxonomic position remains unresolved: however, it most likely would be within subclade IV corresponding to the section Xanthobatrachium.
Threatened status -As a member of the fragile communities of aquatic and semiaquatic temporary habitats (especially inland salt marshes) and because of its inconstant appearance, which is greatly influenced by the groundwater level fluctuations and changing weather conditions, information about the global distribution and population trends of R. polyphyllus are not known completely.However, the taxon is included in the European Red List of Vascular Plants (Bilz et al., 2011) and the IUCN Red List of Threatened Species under category DD (data deficient).The population trend is assesed on global level to be decreasing (Lansdown, 2011).In Slovakia it has the status of a critically endangered (CR) taxon (Feráková et al., 2001) and with the last record from 1964, it seems to have disappeared (P. Eliáš, pers. comm.).In Hungary, it is evaluated as a near-threatened (NT) taxon (Király, 2007).Further investigations concerning population trends and distribution are needed to fulfill the IUCN Red List Categories and Criteria (2001) and to define the threatened status of R. polyphyllus in Serbia.