An earliest record of vascular plants is from Devonian of Canada (Gaspe Peninsula, Quebec). Although the compressions were fragmentary, a reconstruction revealed slender axes arising from a subterranean rhizome system (Fig. 7.3A). The rhizome lacked roots but had rhizoids. The aerial axes were dichotomously branched with scale-like appendages and terminated into sporangia. Because of its similarity with Psilotum. the plant [...]
In this article we will discuss about the anatomy of psilotum with the help of a suitable diagram. Growth of rhizome and aerial branches takes place by divisions of a single apical cell. During dichotomy it divides equally, forming two apical cells which result in two meristems. Internal structure of rhizome varies with its diameter. The slender rhizome (about 1 [...]
In this article we will discuss about the anatomy of selaginella with the help of a suitable diagram. Apical growth takes place by a single cell and its derivatives or by an apical meristem, comprising a group of cells. Branching occurs by a bifurcation of shoot apex into two apices, one of which overtops the other resulting in anistomous branching. [...]