Hygrophila polysperma from South-East Asia is one of the hardiest aquarium plants available. Stems become 25-40 cm and 4-8 cm wide. It is particularly good for beginners because it grows in almost all conditions. It normally grows so fast that it is important to prevent it from crowding out other plants. The shoots must be pinched out regularly. Leaves lying on the surface form small new plants. Hygrophila polysperma varies considerably in leaf shape and color, depending to some extent on the light supplied.e.