Aristolochiaceae
M. QAISER
Department of Botany, University of Karachi, Karachi-32.
Climbing shrubs or erect, low or prostrate herbs. Leaves alternate, entire or 3-5 lobed, exstipulate, petiolate. Inflorescence solitary axillary, racemose or flowers in clusters. Flowers bisexual, actinomorphic or zygomorphic, epigynous. Perianth usually petaloid, brownish or purple, 3-lobed or with a unilateral limb, sometimes an inner whorl of 3 teeth present. Stamens 6-, free or adnate to the style forming a gynostegium; filaments short and thick or hardly separable from gynostegium; anthers free or united with the style with 2 parallel loculi, extrorse, dehiscing longitudinally. Ovary inferior, partly or completely partitioned into 4-6 loculi, placentation parietal or axile; ovules indefinite in each locules, anatropous horizontal or pendulous, style, short and stout; stigmas as many as the carpels. Fruit a septicidal capsule, dehiscing basally; seeds numerous, variable in form; endosperm copious and fleshy with a small embryo.
A mainly tropical family with 6 genera and about 450 species, represented in Pakistan by the following genus and 3 species.
Acknowledgements: We are grateful to the United States Department of Agriculture for financing this research under Pl.480. Thanks arc also due to Mr. I.C. Hedge and Miss J.Lamond of the Royal Botanic Garden, Edinburgh, for their helpful suggestions.
