Annual, biennial or perennial herbs, very rarely shrubs or small trees, usually with milky or coloured latex. Leaves usually alternate, rarely opposite or whorled, exstipulate, mostly dissected, pinnately or palmately lobed. Infloresence basically cymose, mostly solitary, rarely subumbellate or paniculate. Flowers usually showy and large, bisexual, regular, hypogynous. Calyx of 2-3 free sepals, rarely completely united, imbricate, caducous. Petals 4-6 (rarely 8-12, or absent), in 1-2(-3) whorls, free, imbricate, sometimes crumpled in bud. Nectaries absent. Stamens indefinite in several whorls (only 4 stamens in subfam. Hypecoideae) free; anthers dithecous, dehiscing lengthwise; filaments filiform to winged and often coloured. Carpels 2-more, fused; ovary unilocular, rarely bilocular, usually with 2-several, incomplete locules; ovules numerous on parietal placenta (rarely solitary and basal, as in Bocconia ), anatropous or campylotropous; style 1 or absent; stigmas as many as the carpels, opposite or alternate with placenta. Fruit mostly a capsule, dehiscing by pores or valves, rarely indehiscent; seeds many, small, with a crested or smooth raphe or arillate; embryo minute; endosperm oily and mealy.
A family of 26 genera and nearly 200 species, distributed mostly in temperate and subtropical regions of northern hemisphere, including western north America and eastern Asia. Only 7 genera and 22 species have been reported from West Pakistan.
Acknowledgements: We are grateful to the United States Department of Agriculture for financing this research under P.L. 480. Thanks are also due to Messrs. B. L. Burtt and J. Cullen of Edinburgh, for their helpful suggestions.