Apocynaceae
S. NAZIMUDDIN AND M. QAISER
Department of Botany, University of Karachi.
Trees, shrubs or twiners, sometimes herbs, with milky juice. Leaves opposite or whorled, rarely alternate or spiral, simple, entire, sometimes glandular on the entire midrib or at the base of the .midrib, stipulate or exstipulate. Inflorescence axillary or of terminal dichasial cymes or racemes. Flowers bisexual, regular, bracteate or apparently ebracteate. Calyx- (4-) 5 lobed, sometimes polysepalous, lobes equal or unequal, imbricate, often glandular inside at the base, corolla (4-) 5 lobed, hypogynous, rotate, salver-form or campanulate, valvate or twisted in bud; sometimes corona appendages present; stamens (4-) 5, usually inserted on the base of corolla tube, included or exserted; filament very short or absent; anther occasionally connivent with stigma; pollen sometimes in tetrads. Pistil one, basically composed of 2 carpels-free or syncarpous, terminating into single stigma, superior or subinferior, mostly unilocular or bilocular with parietal placentation, rarely bilocular with axile placentation, ovules one to many; style simple or divided at base, stigma large and of various types, mostly umbraculiform below and capitate or pentagonal above. Fruit a fleshy or dry drupe, berry, samara or follicles. Seeds 1 to many, pubescent, winged or apically comose.
A family of 300 genera and nearly 2000 species distributed in tropical and subtropical regions of both hemispheres, represented in Pakistan by 6 native genera (with 6 species) and 13 cultivated genera (with 20 species).
Acknowledgements: We are grateful to the United States Department of Agriculture for financing this research under PL-480. Thanks are also due to Mr. I. C. Hedge of the Royal Botanic Gardens, Edinburgh, for going through the manuscript.
