Development of the Pollen in Some Asclepiadaceae

Abstract

The development of the sporangia in the Asclepiadaceae studied is the same in general as in other plants, while there are no indications of the phylogenetic history of the reduction in number. The primary sporogenous cells without further division become the pollen mother cells. The latter divide each into four with the usual phenomena accompanying tetrad division, but through mutual adjustment and the close adherence of the microspores the evidences of grouping are lost.