Pteridophytes, Variously Called As Primitive Land Plants, Pioneer Vascular Plants Or Early Land Plants, Represent A Group Of Plants In Turmoil. They Have Served As Nature'S Experimental Group Manifesting Patterns Of A Plant Group Adapting Itself From An Aquatic To Terrestrial Existence. This Aspect Of Plant Morpphology, Considered To Be The Central Theme Dominating Botany Till The Fifties Did Suffer A Decline In Emphasis In The Latter Half Of This Century.