Abstract

LEPIDODENDRALES A FASCINATING EARLY FOSSIL PTERIDOPHYTIC WORLD

Dr. Teena Agrawal*

Abstract

Pteridohpytes are the very valuable creation of the nature. They have the first evolved true vascular system in the evolution of the plant life. Seed and fruit formation are absent in whole of the group, the whole of the lines has been divided in the four groups among them Psilophyta, lycophyta and sphenophyta and pterophyta are the main cladistesc of the evolution, these plants with sporophytes which have the roots, stem and spirally arranged leaves. stele system is the protostelic or in some of the cases it is polystelic. Homospory is common in most of genera however in some of the genera Heterospory is the significant feature. Lepidodendrales was the fossil empire in the lower and the upper carboniferous time period, they were the large and the giant trees with the crown of the leaves on the tops, Heterospory and the approximation to the seed has been reached in the majority of the cases, they represent the very important early lines of the evolution of the many plant parts.

Keywords: Heterospory, Fossil plants, Protostele, polystele, sporophytes.