Chapter 21, Problem 25A

Summary Introduction

To write:

The difference between Division Pterophyta and Division Lycophyta.

Introduction:

The seedless vascular plants group is one of the three plant groups with vascular tissues. Seedless vascular plants exhibit a great diversity of form and size. Most club mosses are small plants, usually less than 30 cm in height. However, tropical tree ferns can grow upto 25 m.

Explanation of Solution

Present-day Lycophyta or clubs of mosses are descendants of the oldest group of vascular plants. Pterophya includes ferns and horse tails. The difference between Pterophyta and Lycophyta are given below.

Pterophyta	Lycophyta
It includes tree ferns, climbing ferns, polupodium, etc.	It includes club mosses, lycopodium, selaginella, etc.
The leaves have megaphylls.	The leaves have microphylls.
They are mostly protosteles.	They are mostly siphonosteles.
Leaves develop with circinate vernation.	Leaves are sharp and pointed.

Conclusion

Thus, the Pterophyta are second largest division of the plant kingdom and Lycophyta are a small extant group of vascular plants.