S. aloides: aquatic; leaves tufted at the bottom of the water, sessile, long, narrow, succulent, bordered by small pointed teeth; flower-bracts with delicate dioecious peduncles, bearing a spathe of two bracts, which enclose several stalked male flowers with twelve or more stamens, and one solitary sessile female. The plant rises to the surface to flower and then sinks again. - Lakes and ditches; common in the fens of the eastern counties. Fl. July.