The ferns appeared on our planet at about the same time as the planetary and horsetail-shaped ferns and have experienced their heyday in the past geological epochs. In the Carboniferous period, for example, there were extensive forests of tree fern thickets, only a few of which have survived to this day. Even today, however, the ferns are still numerous, with around 300 genera and more than 10,000 species.
FERN SPECIES AND SHAPES
Ferns are very widespread and can be found in the temperate zone, and in the tropics, and in the Arctic, they are not present only in very arid areas of the planet. Among the ferns, there are species that have changed over to the waterway of life. They either take root at the bottom of the reservoir or swim on the surface.
Almost all ferns, except for a few species, are perennial plants. The stem of most of them is an underground rhizome. The roots are only additive, coming from the rhizome or above-ground stems. Leaves in ferns are called ways, they are very diverse.
Leaf lengths of different species range from a few millimeters to a dozen meters. Fern leaves combine two functions - photosynthesis and sporonentation, and very often ordinary (sterile) leaves differ in shape from leaves with springs. The fern of deer horns has wide and round sterile leaves; dying they form "pockets" for water and humus accumulation. And the spore-bearing leaves of this fern really resemble branched horns. Different types of ferns are used by people for decorative and medicinal purposes, some are used in the manufacture of fertilizers, and young fern shoots are used as food.
DOES THE FERN BLOOM?
According to the folk legend, fern plants bloom on the night of Ivan Kupala, and those who can find this miracle flower will be lucky enough to find a rich treasure. In fact, however, fern plants do not have any flowers. The fern reproduction is similar to the reproduction of ferns and horsetails, but ferns do not have special spore-bearing spikelets. Disputes are formed in springs located on the lower side of leaves (in extinct ferns they were at the ends of branches). Once on the ground, spores give life to a tiny green plate of gametophyte (in ferns it is called "germ"), which is entrusted with the function of sexual reproduction.
Fern plants are surprisingly diverse, but most of them have young leaves curled up with a snail.
Sperm cells move in the water and fertilize the egg, after which a young fern develops from it. Where did the legend come from? Perhaps the source of the legend is the fern ostrich feather, which has very lush and large leaves (up to 1.5 m). At the beginning of July, poisonous leaves like ostrich feathers grow out of the middle of the rosette. They differ from the basic length and color - there are yellowish, brownish. Their rosette is somewhat similar to a flower. The petals of a large flower resemble the poisonous leaves of the fern Brazilian derbyanka, painted in pink.
In Russia, the common fern eagle is widely spread. Such a name was given to the plant for the similarity of the leaf shape with the wing of a big bird, and according to another version - because on the cut of the petiole the vascular bundles form a figure resembling a two-headed eagle. This fern reaches a height of 1.5 m, never bunches and has long underground rhizomes. Most often the eagle grows, forming huge thickets in light coniferous or birch forests. In the XIX century. in many countries of the world from the dried rhizomes of the eagle baked bread.