水绵是遍布于沼泽、湖泊和其它淡水水域的一类沉生性绿藻植物。因其适生于淡水轻质盐土的静水环境，所以在我国沿海及北方大部分农垦稻田危害较重，是我国重要的区域性的稻田杂草。北方地区稻田水绵常见的有两种：一是网水绵（Hydrodictyonspp），俗称蛤镇被，属于水网藻科（Hy Molasses is a group of submerged green algae plants found in swamps, lakes and other freshwater waters. Because of its adaptability to freshwater light saline soil in the still water environment, so in our coastal areas and northern most of the reclamation paddy field more harmful, is our country’s important regional paddy weeds. There are two common types of paddy fields in northern China. One is Hydrodictyonspp, commonly known as clams,