Fern is a green, nonflowering plant that grows in most parts of the country.There are approximately 10,000 species
worldwide.Most grow in damp,shady areas.In the tropics, they are common on trunks, and brances of trees.They belong to class Filicopsida, division Pteridophyta
PARTS OF THE FERNS
Stem- stores food.It may grow upright above the ground or horizontal along the ground or even underground. Rhizomes are stems that grow along the ground or underground.Fern stem may grow slowly and may live 100 years or more.
Roots- anchor the stem to the ground.It also absorbs water and nutrients from the ground.It may live a long time as well
Leaves-make food by photosynthesis. It carry tiny structures called sporangia, which have stalks, and capsules that contain spores.Each cluster of sporangia is called sorus, and all clusters on the fern are called sori.Ferns are only plants that have sori.
Life cycle of the fern
SPOROPHYTE- is stage of the fern the asexual.It produces leaves with sporangia.When they mature,they split open in dry air and release spores.Most fern spores grow best in shadd,moist soil.It grows into tiny,heart-shaped plant called gametophyte.
GAMETOPHYTE- its growth begins the sexual stage. It is usually called
prothallium.After a few weeks,prothallium develops gametes.Antheridium produces sperm.Archegonia
produce the egg.In most ferns,both archegonia and antheridium are in the same prothallium.When the sperm matures, it swim into archegonium on the same prothallium or at other prothallium.It joins the egg to produce zygote. It grows within the archegonium to develop into embryo.Part of the embryo absorbs food from prothallium while other parts produce stem,root and leaf .It draws energy from the prothallium until the root enters the ground
TYPES OF FERNS
BRACKEN- commonest in Europe and North America.It spreads quickly on the heath and uncultivated areas.It is poisonous to farm animals .scientific name: Pteridium aquilinum
ROYAL ferns-with fronds up to meters long,divided to many narrow leflets.It grows in swampy areas in Europe,Africa, North and south America. Scientific name; Osmunda regalis
TREE ferns- grow in rainforests of Africa,Australia,New Zealand,Southeast Asia, and south America.They have woody trunks and some species grow as tall as 25 meters. At the top of the trunk, their fronds spread out like a fan.They belong to family Cyatheaceae and Dicksoniaceae.
FILMY FERNS-belongs to family Hymenophylaceae,small, thin,translucent leaves only 1 mm long.They live in very moist places
WATER FERNS-floats on the surface of water.Their leaves have fine hairs which prevent them to become waterlogged and keep them afloat. Roots hang free in the water below.
STAG’S HORN-epiphytes on trees.they produce a tight bunch of leaves, which trap the water and humus needed for growth.They belong to genus Platycerium
ADDER’S TONGUE FERN AND MOONWORT- small, grows amongst grasses.The leaves are simple and undivided. They are also named Ophioglossum vulgatum and Botrychium lunaria
CLOVER FERNS-look like 4-leaf clover. They grow in swampy areas or in shallow water.They belong to genus Marsilea. their fronds spread out like a fan
World Book Inc, 1992,2 pages