A contribution to the life-history of Vahlia viscosa, Roxb., and Vahlia oldenlandioides, Roxb.

Abstract

The haploid chromosome number of Vahlia oldenlandioides has been confirmed to be 6, and that of V. viscosa has been determined to be 9. The origin and development of the microsporangium, the embryo-sac, the endosperm and the embryo is described in detail; both Vahlia viscosa and V. oldenlandioides are found to be quite similar. In both the species of Vahlia investigated, the endosperm is cellular and there are four uninucleate chalazal endosperm haustorial cells in both. No relationship could be established between the divison of the family on the basis of the type of endosperm development with (i) division of the family by taxonomists on morphological grounds and (ii) the chromosome numbers known in the family. For a cytotaxonomical approach, cytological details like secondary association, etc., of which no information is now available, are suggested to be a necessary prerequisite. The role of the integumentary tapetum is discussed in the light of its correlation to the nucellus and the endosperm.