When you think of forests and woods, you can picture trees, abundant lush green ferns, and other plants. But trust me the first thing that you will notice is the abundant foliage of fern plants. These ferns, in biological terms, are nothing but the pteridophytes, belonging to the division Pteridophyta of the plant kingdom.
What are Pteridophytes?
These plants are the ones that do not have any flowers or seeds. Hence they are also called as Cryptogams. They include ferns and horsetails. In fact, they can be considered as the first terrestrial vascular plants, showing the presence of the vascular tissue, xylem, and phloem. They can be found in mostly in damp and shady places. Most ferns are grown as ornamental plants.
Features of Pteridophytes
Pteridophytes display differentiation. The plant body can be divided into a true root, stem, and leaves. A saprophyte is the main plant body here. Some of the species belonging to this division have small leaves called as the microphylls. For example, Selaginella. Megaphylls are the large leaves that some pteridophytes have. For Example Fern plants. The main plant bears the sporangia. These bear some leaf-like appendages called the sporophylls. In a few species such as Selaginella and Equisetum, the sporophylls form compact structures called cones or strobili.
Reproduction in Pteridophytes
Pteridophytes show a true alternation of generations. Here, the dominant sporophyte produces spores through meiosis. The gametophyte generation forms gametes by mitosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate and give rise to gametophytes.
These gametophytes are free-living, multicellular and photosynthetic. They are called as the prothallus. Generally, the gametophytes require damp and cool places to grow, due to their dependence on water. For this very reason, the growth of pteridophytes is confined to certain geographical areas.
The male sex organs are called the antheridia and the female sex organs are called the archegonia. The male gametes are called the antherozoids, which are released by the antheridia. Antherozoids can get transferred to the archegonia which are the female sex organs, only in the presence of water. Once the fusion of the gametes occurs, a zygote is formed. This zygote produces the sporophyte, after division.
When the spores of the plants are similar then these plants are called homosporous plants. Heterosporous plants are the ones that have two different kinds of spores. They are the megaspores and the microspores. In these heterosporous plants, the megaspores and microspores germinate and give female and male gametophytes respectively.
Classification of Pteridophytes
There are four classes, namely:
Learn more about the Life Cycle of Plant here in detail.
Solved Question For You
Q: Why are pteridophytes common in moist and damp areas?
Ans: Pteridophytes have a dependence on water. Reproduction and fusion of gametes can happen in the presence of water. In humid and damp conditions, fertilization occurs effectively and the reproduction is more. Hence they can proliferate more.