Pteridophytes

Pteridophytes are commonly known as Ferns. There are around 12,000 species of Ferns, many of them are generally used a decoration / ornamental plants.

Position of Pteridophytes in Evolution

In the evolutionary stages, Ferns are next advanced level after Bryophytes. Bryophytes don’t have the vascular tissues, but the Ferns have both xylem and phloem, thus they are the first vascular plants in terms of evolution of plant species. They have stems, leaves, and roots like other vascular plants. Further, in case of the Bryophytes, the dominant phase of life is gametophytes. This reverses from Pteridophytes ONWARDS. Thus in Pteridophytes, Gymnosperms and Angiosperms, the dominant phase of life is Sporophyte. This Sporophyte is NOT only independent but also long lived.

Pteridophytes differ from the advanced plants on the basis of the Reproduction procedures. They differ from gymnosperms and angiosperms as they do not have neither flowers nor seeds.

Economic Importance

Most of the Pteridophytes have ornamental value; they are grown as ornamental plants in gardens and homes. Some Pteridophytes such as Marsilea are rich source of starch and used as food material. Parts of Pteridium aquilinum or Pteridium esculentum, are used as a cooked vegetable in Japan and are believed to be responsible for the high rate of stomach cancer in Japan. It is also one of the world’s most important agricultural weeds, especially in the British highlands, and often poisons cattle and horses. Dryopteris filix-mas is used an anti-helminth means anti worm, used in Pharmacy.

Biofertilizer

The smallest fern Azolla has the capability of Nitrogen Fixation is used as a biofertilizers, especially in parts of Southeast Asia. Azolla has been used for thousands of years in China in paddy cultivation. Azolla is also known as Mosquito fern because of a myth, that when this plant is in bloom, no mosquito can cross its covering to the water in the water body to lay eggs.