Ontogeny of Microsporangium and Development of Male Gametophyte in Malaxis Versicolor (LINDL.) Abeyw (Orchidaceae)

The anther in Malaxis versicolor (Lindl.) Abeyw. is dithecous and tetrasporangiate. Its wall development conforms to the monocotyledonous type (Davis, 1966). Mass of densely protoplasmic cells represents the archesporium. Each such archesporium develops into pollinium. The anther wall is 4-layered. The endothecial cells develop one or two ring like radially disposed thickenings on the inner walls. Tapetal cells are uninucleate and dual in origin. Simultaneous cytokinesis results in tetrahedral and rhomboidal pollen tetrads. At the time of release of pollnia pollen grain attain 2celled stage.