Distribution Pattern of Nitellopsis obtusa (Desv.) J.Groves (Charophyta, Charales) in Ukraine

The analysis of literature and original data on the distribution pattern of <i>Nitellopsis obtusa</i> (Desv.) J.Groves (<i>Charophyta, Charales</i>) in Ukraine is presented. This relict species is regionally red listed in its native Eurasian range within temperate and subtropical latitudes from Portugal to Japan, but invasive in North America, in the Great Lakes region, because of an accidental introduction in 20<sup>th</sup> century. In Central and Eastern Europe <i>N. obtusa </i>is a rather common species, though it is found everywhere rather than sporadically. Its distribution is limited by such factors as type of water body, total mineralization, ionic composition of water and pH. Totally 26 localities of <i>N. obtusa</i> were recorded in Ukraine. A list of localities and a map of the distribution of <i>N. obtusa</i> in Ukraine were compiled and analyzed. All localities were found within Ukrainian Polissya (Mixed Forest), Forest Steppe and Steppe zones of Ukraine. However, the characteristic of their location confirms the trend of distribution of <i>N. obtusa </i>in Ukraine exclusively in the valleys of large rivers, that can be explain by the absence of large lakes with stable hydrological and hydrochemical regimes, as well as ecological and biological features of the species.