The fern is in a species of over 20,000 plants classified in the division of Pteridophyta or Filicophyta. The term pteridophyte is traditionally used to describe the seedless vascular plants.
Ferns are vascular plants differing from seed plants and have life cycles called "alternation of generations", which is characterized by an organism plant and an organism with a single set of chromosomes plant life phase, which are also free-living organisms.
The cycle of life for the fern begins with the first phase called plant or organism phase where the fern produces an organism with a single set of chromosomes spores. The spores grow by cell division into a plant life that generally has photosynthetic plant-baring spores. The plant life produces reproductive cells that often are both egg and sperm on the same region by cell division. Flagellate sperm that remains attached to the plant-baring spores fertilizes the egg. The growing fern egg is called an organism zygote and grows by cell division into a typical fern plant.
Ferns like to grow in moist shady woodland areas while others live in variety of locations including mountain regions, dry deserts rock surfaces, bodies of water, and in wide-open fields. Some varieties of ferns are similar to weeds such as the British Highland fern called the bracken fern and the mosquito fern or Azolla fern.
There are four standard habitats ferns grow in such as moist, shady forests, swamps, tropical trees and acidy wetlands where the sun is not commonly exposed to the plant life.
Many ferns rely on the associations of the mycorrhizal fungi. The ferns grown in specific pH ranges with higher levels of acid such as the bulblet bladder fern are only found on limestone.
Ferns consist of stems that are underground spreading rootstock yet sometimes are above ground spreading runner or above ground erect partially woody trunk that reaches out to other species.
The fern has leaves that are the green photosynthetic area of the plant. The fern leaf is often called the frond. New leaves on the fern generally expand by unrolling from a tight corkscrew shape called fiddlehead or crosier. The process of the leaves uncurling is called circinate cernation.
The leaves have three types. Trophophyll is a not producing spore plant but produces sugars through photosynthesis. Correspondent is typically green leaves of the seed plants.
Sporophyl does produce spores. The leaves are similar to the pinecone. Sporophyllis of ferns are not a specialized type of fern. They look like trophophylls and create sugar as well.
Brophophyll is the leaves that produce large amounts of spores. Their leaves are larger than the other ferns yet still resemble the trophopylls.
Roots are the underground parts of the fern that are non-photosynthetic to take the nutrients and water from the soil. The roots are fibrous and similar to the roots of a seed plant.
The plant lives are different from seed plants since they consist of plant baring spore that is a green part with one thick cell, which is heart or kidney shaped. It has dimensions of 3-10 mm long and 2-8 mm wide. The plants baring spores generates reproductive cells by the male sex organ of the spore producing plant and a flat-shaped formation that produces one egg at the bottom. The egg makes contact with the sperm as the sperm swims downward in the neck of the plant towards the egg.
Rhoizoid are root like structures that have one elongated cells that absorbs water and mineral salts for the entire structure. Rhizoids secure the plant-baring spores to the soil firmly.