Plant Systematics Practical Book

Abstract

The word Pteridophyta is of Greek origin. Pteron means “feather” and Phyton means plant. The plants of this group have feather-like fronds (leaves). The Pteridophytes are an assemblage of flowerless, seedless, spore-bearing vascular plants that have successfully invaded the land. Pteridophytes have a long fossil history on our planet. They are known from as far back as 380 million years. Fossils of pteridophytes have been obtained from rock strata belonging to Silurian and Devonian periods of the Palaeozoic era. So the Palaeozoic era is sometimes also called the “Age of Pteridophyta”. The fossil Pteridophytes were herbaceous as well as arborescent. The tree ferns, giant horse tails and arborescent lycopods dominated the swampy landscapes of the ancient age. The present-day lycopods are the mere relicts the Lepidodendron like fossil arborescent lycopods. Only present-day ferns have the nearby stature of their ancestors. Psilotum and Tmesipteris are two surviving remains of psilopsids, conserve the primitive features of the first land plants.