YASIN J. NASIR
National Herbarium, Agricultural Research Council,
Trees, herbs or shrubs. Leaves opposite or alternate, simple, exstipulate. Inflorescence cymose. Flowers hermaphrodite or unisexual, often bracteate; bracts showy and petaloid or inconspicuous. Perianth 5-lobed, tubular, gamophyllous, petaloid, lower half (the anthocarp) persistent. Stamens 5, but may be, more or less, alternating with the lobes; filaments often unequal, anthers bilocular, dehiscing longitudinally. Pistil monocarpellary, ovary unilocular, with a solitary basal ovule. Fruit a nut, utricle or an achene, enclosed in the anthocarp. Seed endospermic.
A family of 30 genera and c. 290 species, in tropical and subtropical parts of both the hemispheres, especially America. Represented in Pakistan by 5 genera and 10 or 11 species. In the key that follows and the descriptions, the term anthocarp stands for the mature fruit and ‘lower half of perianth’ for the anthocarp at anthesis.
Acknowledgements: We are grateful to the United States Department of Agriculture for financing this research under P.L. 480. Thanks are also due to Dr. F.R. Fosberg, Smithsonian Institution, Washington, Mr. R.D. Meikle, Herbarium, Royal Botanic Gardens, Kew, Mr. B.L. Burtt, Mr. I.C. Hedge and Miss J. Lamond of the Royal Botanic Garden, Edinburgh for going through the manuscript and giving valuable suggestions.