Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species (Christenhusz & Byng 2016 ), that including a number of species of aquatic plant, for instance the tape-grasses, the well known Canadian waterweed and frogbit Hydrocharis morsus-ranae. The family includes both fresh water and marine aquatics, although of the seventeen species currently recognised only three are marine. They are found throughout the world in a wide variety of habitats, but are primarily tropical.