Introduction: Pteridophytes is a group of primitive land plants belongs to the cryptogams. They are the first evolved plant group with vascular tissue system for the conduction of water and food materials. Due to the presence of vascular tissues, they are called as vascular cryptogams. The term pteridophyta is derived from two words ‘Pterori' meaning feather and ‘phytan’ meaning plant. Thus pteridophytes are the plants with feather like leaves. Pteridophytes include primitive living and fossil vascular plants.

Habit and Habitat: Most of the pteridophytes are annual, terrestrial and herbaceous plants (e.g., Psilotum, Selaginella, Lycopodium). Some are large perennial trees (e.g., Angiopteris, Alsophila), aquatic (e.g., Azolla, Marsilea, Isoetes, Salvinia), xerophytes (Selaginella), halophytes (e.g.,Acrostichum). Morphology :    The sporophytic plant body is differentiated into stem, root and leaves. Most of the pteridophytes plants are with herbaceous stem, some are woody. The stem is usually branched, the branching may be monopodial or dichotomous. The primary roots are ephemeral (short - lived) and they are immediately replaced by adventitious roots.

Based on the size, three types of leaves are found in pteridophytes:

1. Scale leaves: Small minute scale - like, leaf, e.g., equisetum.
2. Small sessile leaves: Leaves are small without leaf stack (petiole), e.g., Lycopodium, Selaginella.
3. Large, petiolate compound leaves: Occurs in true ferns, e.g., Pteris, Angiopteris.

Based on the internal structure of leaves, the pteridophytes are classified into two groups:
1. Microphyllous pteridophytes: Leaves are small and simple, possess a single vein in the middle region. No leaf gap occurs in the stem, e.g., Lycopodium, Selaginella.

2. Macrophyllous Pteridophytes: Leaves are large and compound, possess complex venation a mesophyll is differentiated into simple and spongy tissue. They form leaf gap on the stem. e.g.,Pteris. Leaves and stem also possess many trichomes hairs. Stomata are present and they are distributed on both upper and lower surface of the leaves.
Vascular Tissues: Root and stem possess well developed vascular system composed of xylem and phloem. The xylem chiefly composed of tracheids and very few parenchyma. Xylem vessels are completely absent. The phloem is made up of sieve cells and phloem parenchyma. Companion cells are absent in the phloem of pteridophyta.

Reproduction and Life Cycle
1. In pteridophytes, the main plant body is sporophyte which bear sporangia that are subtended by leaf like appendages called sporophylls. In some cases the sporophylls may form distinct compact structures called strobili or cones (e.g., Selaginella, Equisetum).

2. The sporangia produce spores by meiosis in spore mother cells. The spores germinate to give rise to inconspicuous, small but multicellular, free living, mostly photosyrithetic thalloid gametophytes called prothallus.

3. These gametophytes require cool, damp, shady places to grow. Because of this specific restricted requirement and the need for water for fertilisation, the spread of living pteridophytes is limited and restricted to narrow geographical regions.

4. The gametophytes bear male and female sex organs called antheridia and archegonia respectively. The antheridia release male gamete called antherozoid which require water to transfer upto the mouth of archegonium. Fusion of male gamete with the egg present in the archegonium result in the formation of zygote.

5. Zygote thereafter produces a multicellular well differentiated sporophyte which is the dominant phase of the pteridophytes. In majority of the pteridophytes, all the spores are of similar kinds, such plants are called homosporous.

6. Some genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous.

7. The megaspores and microspores germinate and give rise to female and male gametophytes respectively. 
The female gametophytes in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos take place within the female gametophytes. This event is a precursier to seed habit, which is considered an important step in evolution.