The new kenophyte in Poland - Lemna minuta Humb., Bonpl. and Kunth

For the first time in Poland two habitats of Lemna minuta were found in 2007. Both of them are located in the warmest south-western region of the country. L. minuta is a North-American kenophyte which has come to Poland probably from Germany. This species grows no bigger than 1-3 mm, which makes it the smallest representative of genus Lemna. The most characteristic features of L. minuta are the lack of purple pigmentation and the presence of only one hardly visible vein in the frond.