Nauji duomenys apie Zannichellia palustris L. ir jos bendrijas Lietuvoje [New data on Zannichellia palustris L. and its communities in Lithuania]. – Botanica Lithuanica, 4(3): 335–340

New Localities of Zannichellia palustris L. in Lithuania as well as species composition of Zannichellia palustris lang 1967 are described. Since 1956 only one locality (Lake Seirijai, Lazdijai district) of Z. palustris has been known. In July of 1997 this species was found growing in Lake Drūkšiai (Zarasai district), August of 1997 – in the Curonian Lagoon and in July of 1998 – in lake Vištytis (Vilkaviškis district) and lake Obelija (Alytus district). In all these water bodies groves Z. palustris of different size were found up to 1 m (more ofen 10-50 cm) depth, on sand, silty sand or sandy silt with the remainder of mollusk shells. The most constant species in Zannichellietum palustris communities were Potamogeton pectinatus, P. berchtoldii, Chara aspera, less constant – P. perfoliatus, Myriophyllum spicatum, Elodea canadensis. In the the phytocenoses of lakes Drūkšiai and Vištytis, as well as Kniaupas Bay in the Curonian Lagoon pondweeds (Potamogeton berchtoldii (more often), P. friesii,and P. rutilus) dominate. In the eastern part of the Curonian Lagoon and sandy shallows of lake Vištytis communities with Chara aspera were distributed. Only lake Vyštytis the phytocoenosis with Ranunculus reptans, and Eliocharis acicularis was found. The groves of Z. palustris usually are covered by Cladophora sp., rarely Enteromorpha intestinalis – characteristic species of Zannichellietum pedicellatae Nordhagen 1957 can by found. In 1957 in lake Seirijai the Z. palustris was found growing with P. palustris.

Keywords: Zannichelliaceae, Zannichellia palustris, Zannichellietum palustris, aquatic macrophytes, Lithuania.