SAOOD OMER & RIZWAN Y. HASHMI
Department of Botany, University of Karachi, Karachi-32
Aquatic or marshy, erect perennial monoecious herbs. Rhizome creeping, submerged, scaly; aerial stem erect, with or without nodes. Leaves radical or cauline, elongated. Inflorescence a terminal, cylindrical, superposed spike; male above and female below, parts separated or sometimes united. Flowers numerous, densely crowded. Male flowers consisting of 1-3 stamens and surrounded by one or more hairs, some representing the perianth; anthers basifixed, linear. Female flowers usually intermixed with clavate pistillodes, covered with hairs and bracts or bracts absent; ovary superior, 1-locular, stipitate; stigma linear or lanceolate. Fruit a follicle, dehiscing longitudinally by a slit. Seed striate.
Unigeneric family, with about 10 species, distributed in marshy and aquatic habitat of both the hemispheres.
Acknowledgements: We are grateful to the authorities of Royal Botanic Gardens, Kew, for sending the specimens on loan. Thanks are due to Prof. C.D.K. Cook (Zurich) and Mr. I.C. Hedge (Edinburgh) for going through the manuscript and offering valuable suggestions. The financial assistance received from United States Department of Agriculture under PL-480 programme with the coordination of Pakistan Agricultural Research Council, Islamabad, is thankfully acknowledged.