POLLEN FLORA OF PAKISTAN - LXVII: ACANTHACEAE

Pollen morphology of 30 species of the family Acanthaceae belonging to 11 genera has been investigated using light and scanning electron microscope. Acanthaceae is a eurypalynous family. Pollen are usually radially symmetrical, isopolar, sub-prolate to prolate rarely prolate-spheroidal or sub-oblate to oblate-spheroidal, generally tricolporate or heterocolporate rarely colpate or porate. Exine ornamentation varies from medium to coarse reticulate, or often lopho-reticulate with luminae perforated to baculate or scabrate. On the basis of apertural type, exine ornamentation and colpal membrane eight distinct pollen types have been recognized viz., Pollen type-I: Barleria cristata-type, Pollen type-II: Blepharis ciliaris-type, Pollen type-III: Hygrophila polysperma – type, Pollen type-IV: Justicia adhatoda-type, Pollen type-V:Lepidagathis incurva-type, Pollen typeVI:Peristrophe paniculata-type, Pollen type-VII:Ruellia patula-type and Pollen type-VIII: Strobilanthes atropurpureus – type. Within the family pollen diversity is significant enough for delimiting the tribes, subtribes and genera.