This family represents the smallest flowering plants (Wolffia). All of the species are aquatic and free floating, with Lemna trisulca being submerged just below the surface of the water. These species may form thick mats in marshes and slow moving water. The flowers are probably rare and very small with staminate flowers of 1 stamen and pistallate flowers of a single unicarpelate, unilocular gynoecium.
Wolffia columbiana Karst. has only been reported officially rarely in the province - during the summers of 1998/1999 the species was noted widely in southern Manitoba in the Red River valley leading to the belief that it is more overlooked (because of its size) than actually rare.
Genera found in Manitoba:
Lemna Spirodela Wolffia