Pteridophyta is a vascular plant family with about 12000 species. Pteridophyta are known as “cryptogams” because, unlike most other members of the Plant Kingdom, they reproduce through spores rather than seeds. Pteridophyta includes ferns, horsetails, and lycophytes.

The only non-flowering seedless plants with vascular tissues are pteridophytes. Psilophyta, Lycophyta, Arthrophyta, and Filicophyta are the four primary classes of Pteridophyta. Pteridophyta will be discussed in depth in this article. 

Pteridophyta

“Pteridophytes are vascular cryptogams with no seeds. They reproduce via spores and can grow to tree-like heights of 30 to 40 feet”. 

In the year 1866, Ernst Haeckel coined the name “Pteridophyta”. 

Characteristics of Ptridophyta

Primal Terrestrial Plants

It is a concept that life began in the seas and evolved to dry land during millions of years of evolution. Pteridophyta, on the other hand, are primitive terrestrial plants that have evolved.

Plant Body

The fundamental plant body is the sporophyte. It’s broken down further into stems, roots, and leaves.

• Stems: The majority of the branches are herbaceous, but some are woody. A monopodial stem or a dichotomous branching stem could be used for the stems.
• Roots: Roots are small and sprout along the rhizomes by accident.
• Leaves: Leaves come in three varieties: scale, small sessile, and huge petiolate compound.

Vascular Plants

Pteridophyta has well-developed vascular tissues. Tracheids make up the xylem, while sieve cells and phloem parenchyma make up the phloem. The tissue, however, is absent of xylem vessels and phloem partner cells.

Sporangia in Sporophytes

Sporophylls, which are leaf-like structures, look after sporangia in sporophytes. The tip of the leaves curls inwards to protect the fragile growing zones. Furthermore, spores are created within the sporangia. Sporophylls can also form cones or strobili, which are compact structures.

Multicellular Sex Organs

The sex organs of Pteridophyta are multicellular. The male sex organ is antheridia, while the female sex organ is archegonia. The prothallus carries the sexual organs. A prothallus is a tiny gametophyte that emerges from spores after they have germinated. 

Alternation of Generation

The Pteridophyta exhibit generational alternation. It can be proven by looking for sporophyte and gametophyte generations in them. The dominant sporophyte uses meiosis to produce spores. In the gametophyte generation, mitosis creates gametes. The life cycle of Pteridophytes and other plants is known as alternation of generations.

Classification of Pteridophytes

Psilophyta

• The most primitive pteridophytes are these.
• They don’t have any roots.
• Instead of roots, rhizoids are found.
• They have spirally arranged lateral appendages such as scales or leaves.
• They’re all the same.
• Multiflagellate antherozoids are present.
• Examples: Psilotum

Lycophyta

• Roots, stems, and leaves make up the plant body.
• Their leaves are microphyllous.
• They are heterosporous in Selaginella or homosporous in Lycopodium.
• Club mosses are another name for these mosses.
• Lycopodium and Selaginella are two examples.

Arthrophyta

• Roots, stems, and leaves make up the plant body.
• They’ve connected the stem’s nodes and internodes.
• They have tiny, scaly leaves that are grouped in whorls at nodes.
• Horsetails are another name for them.
• The only extant genus in this class is Equisetum.
• They are homosporous in nature.
• Equisetum is an example.

Filicophyta

• Roots, stems, and leaves make up the plant body.
• Their leaves are pinnately complex and circinate.
• They can be found in a variety of environments.
• They are heterosporous as well as homosporous.
• They’re also called ferns.
• The largest group of pteridophytes and the most developed.
• Pteris, Dryopteris are two examples.

Life Cycle

Pteridophyta exhibit generational alternation. Pteridophytes have a life cycle that is similar to that of seed-bearing plants; however, unlike mosses and seed plants, they have distinct and free-living generations of haploid gametophyte and diploid sporophyte. A Pteridophyta’s life cycle is summarized here.

• Since they are flowerless and seedless, Pteridophyta reproduces by spores.
• At first, spores are released into the atmosphere.
• Spores develop into haploid gametophytes with both male and female sex organs in the shape of a heart.
• As soon as the immature gametophyte grows, the sex organs become active.
• In ferns, the male reproductive organ is antheridium (which produces sperm), while the female reproductive organ is archegonium (which produces eggs).
• Water is essential for fern reproduction in order for the sperm to circulate and fertilize the egg.
• Mitosis is the process through which a fertilized egg, or zygote, forms roots, stems, and a new sporophyte (cell division).

Conclusion

In a word, we can state that Pteridophyta is one of the oldest plant families on the planet. They can only be found in terrestrial environments. They’re also known as one of the first “real” plants to adapt to land life. 

They are also the earliest terrestrial plants to have a fully developed vascular system. Ferns are a type of pteridophyte that can be found in abundance all around us. Habitat, plant body, stem, roots, leaves, vascular tissues, and reproduction are all characteristics of Pteridophyta.