In this article we will discuss about the phylogenetic organs of flower. Most Taxonomists agree that angiosperms form a natural group. They are monophyletic that is, their origin is from one ancestor only. But the ancestor is to be identified definitely. The ancestral organs from where the extant floral parts evolved are not known. Wilson (1982) regards that angiosperms evolved [...]
In this article we will discuss about the process of transition in flowers, explained with the help of suitable diagrams. Reproductive apex exhibits plastochron size fluctuations during the development of floral parts/primordia. The apex may widen and become slightly flattened. In Liriodendron the apex becomes conical and elongated. Smith (1966) reported the horizontal and vertical enlargement of the apex in [...]
In this article we will study about the secondary structures of plant with the help of suitable diagrams. A. Stem of Aristo-lochia Sp. (Fig. 7.1): In the primary condition the stem reveals the features of a typical dicotyledonous stem, i.e., presence of uniseriate epidermis, well differentiated cortex, ring arrangement of vascular bundles which are distinctly collateral and open type, [...]