POLLEN FLORA OF PAKISTAN–LXXI. ONAGRACEAE

Abstract

Pollen morphology of three genera representing 13 species of the family Onagraceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains usually tetrads rarely monads, radially symmetrical, isopolar, mostly oblate rarely spheroidal, porate sexine thicker tor thinner than nexine. Tectal surface mostly foveolate-rugulate with viscin threads. On the basis of size and tectum types 3 distinct pollen types are recognized, viz., Epilobium angustifolium– type, Circaea alpina–type and Oenothera affinis–type.