Abbildungen der in Deutschland und den angrenzenden gebieten vorkommenden grundformen der orchideenartenBerlin,R. Friedlnder & sohn,1904.biodiversitylibrary.org/page/15349970
Lesser duckweed (Lemna minor). Found in ponds, lakes, and stagnant waters throughout North America below 58 deg. N..lat. Also in Europe (After Britton & Brown)