A high polyploid Eleocharis uniglumis sl (Cyperaceae) from Central and Southeastern Europe

Chromosome counts and morphological measurements were carried out on Eleocharis uniglumis s. 1. samples from nine populations in Slovakia, Hungary, Austria and Croatia. A high polyploid Eleocharis uniglumis s.1. (2n=71-88) was found on halophilous sites: in western Slovakia (Svatojursky Sdr near Bratislava; 2n=71-78), on the Hungarian and Austrian shores of Lake Neusiedlersee (Hungary: Hidegseg; Austria: Tadten, St. Andra am Zicksee; 2n=71-82), and on the Croatian island of Krk, (shores of Lake Jezero and Lake Ponikve; 2n=80-88). These high polyploid populations have the same ploidy level as E. uniglumis subsp. sterneri, described as endemic to the islands of Oland and Gotland. Morphological similarities between the high polyploids and subsp. sterneri were found both in quantitative features correlated with ploidy level (stomatal length, anther length and fertile glume length) and in other characters (number of perianth bristles, broad sterile glume margins). Differences were detected in the receptacle density and in the length of perianth bristles compared to the length of the achene. Intermediate somatic chromosome numbers 2n=60-70, corresponding to Scandinavian hybrids between E. uniglumis subsp. uniglumis and E, uniglumis subsp. sterneri, were found near Neusiedlersee (Austria: Apetlon, Tadten; Hungary: Hidegseg, Hegyko). These (karyologically intermediate) plants have intermediate stomatal lengths. In other features they are similar to the Central European high polyploids. Eleocharis uniglumis subsp. uniglumis (2n=46) was found here as well (Hungary: Fertorakos).