KHADIJA AZIZ and S.I. ALI
Department of Botany, University of Karachi, Karachi.
Aquatic herbs, monoecious or dioecious, submerged in fresh, brackish or salt waters. Rhizome slender, creeping. Leaves alternate, opposite or more or less whorled, linear, base sheathing; sheaths mostly ligulate at the apex; flower¬ing leaves sometimes reduced to sheaths. Flowers solitary or in axillary cymes. Perianth absent, cupular or of 3 free small scales. Male flowers with 1-3 stamens; pollen globose. Female flowers with 1-9 free carpels; carpel unilocular, with solitary pendulous ovule; style short or long, simple or 2-4 lobed, capitate, peltate, spathulate or ligulate. Fruit sessile or stipitate, indehiscent. Seed pendulous, without endosperm.
A family of 3 genera and about 6 species, widely distributed in fresh, brac¬kish or salt waters.
Acknowledgement: We are grateful to the United States Department of Agriculture for financing this research under P.L. 480.