Microsporogenesis of Polypleurum wallichi (R. Brown ex. Griff.) Warm. (Podostemaceae) growing in northeast India

Abstract

In P. wallichii, the flowers are cleistogamous, enclosed by a thin membranous spathe. The two anthers are borne on a forked filament placed adjoining to the stigmatic lobes. Ontogenetically the two anthers developed separately; because of intercalary growth, it becomes bifid. The archesporial cell comprises of uniseriate rows of cells, the anther wall consists of a very thin epidermis, unilay-ered endothecium with fibrous thickenings and the tapetum with uni- and binucleate cells. The anther wall development is reduced type, middle layers are absent. The connective tissues also acquire fibrous thickenings. Cytokinesis of microspore mother cell is successive type within a dis-tinct callose wall. Pollen grains are dispersed in dyads with minute and dense granular exine.