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Golosemennye

220 with superfluous millions years ago these primitive plants dominated in flora of our planet. Their number treat kindly a fur-tree familiar to us, found ginkgo and huge sequoias.

Golosemennye - ancient group of plants. They ruled on a planet not less than 120 million years (220-100 million years ago) - up to occurrence of floral plants. It is time their blossoming for a long time passed, but representatives of five groups, among which - the highest and exotic trees on the Earth up to now have remained.

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The Majority golosemjannyh are evergreen trees or bushes at which semjazachatki, or semjapochki, are in direct contact to air thanks to what there is their direct pollination. The scientific name of these plants is formed of two Greek words: "gymnos" that means "уюы№щ" and "spermas" - "ёхьхэр".

Man's and female plants grow separately more often, and their reproductive bodies are in cones. Man's cones develop a large quantity of tiny kernels of the pollen containing man's reproductive cages (gamete). Pollen is transferred by a wind on cones of female plants and impregnates them semjapochki.


Coniferous giants

Golosemjannye is easy for distinguishing Coniferous breeds on shishkovidnym tsvetkam and to fruit bodies (many know how the fir cone), and also to needle leaves looks. Usually coniferous trees are very high, and ability to overtake neighbours in rivalry for a sunlight was one of the reasons of their successful development.

Some largest and oldest plants of a planet concern number of the coniferous. The highest trees in the world - the Californian sequoias (Sequoia sempervirens). the Height of one such giant in a valley of Redvudkrik that in the State of California, exceeds 112м. Huge vellingtonija (Sequoiadendron giganteum) concedes growth to a sequoia a little, but differs in the extreme thickness of a trunk. The awned pine (Pinus aristata), that grows in Rocky mountains, there live some millenia; the age of some awned pines of Arizonsky desert makes kind 4000 years. But the most ancient long-liver of a planet is a pine Pinus longaeva: one representative of this kind totals 4900 years!


Listopadnye coniferous breeds

Almost all coniferous are evergreen plants, but some known kinds dump needles for the winter. Their number concern a larch (Larix decidua) and the marsh cypress (Taxodium distichum), which grows in boggy places (for example, the reserve Everglejds in the State of Florida) and lets out similar to pegs sticking out of the earth the air roots eating atmospheric oxygen.

The Southern hemisphere is rather poor coniferous breeds, and the exception is made, perhaps, only by the Chilean araucaria (Araucaria araucana). This beautiful coniferous tree with fancifully bent branches willingly grow up in gardens and parks. Yews (Taxus) and their distant Asian relatives, the pines nicknamed "ъюЁютішьш §тюё=рьш" (Cephalotaxus), enter into not numerous isolated group of plants with fleshy " уюфрьш" instead of cones.

On different plants of a yew appear man's and pistillate flowers, and the developed seed acquires fleshy prisemjannikom (arillusom). All plant is poisonous, but birds without harm for themselves eat its bright red " уюф№" also promote distribution of seeds.


Sagovniki or tsikadovye

Sagovniki is an ancient and elementary group golosemjannyh plants. On appearance they are more similar to palm trees, and them sometimes name treelike ferns. Often enough they grow till the size of a small tree (seldom above 10, and the direct stalk is topped by a bunch of huge plumose, quite often prickly leaves. Cones are formed in the plant center in an original nest of palmlike leaves and sometimes grow at length to 60 the Majority sagovnikov see grows in tropics, but in Great Britain the kind Cycas revoluta is sometimes grown up in greenhouses.


Ginkgo

Golosemjannye Is no time considered died out in the wild nature ginkgo (Ginkgo biloba) is nicknamed "тхэхЁшэ№ь тюыюёюь" for similarity of its foliage to a fern of the same name and today meets as a valuable ornament of botanical gardens is more often. Man's trees for seeds of female individuals exude a disgusting smell are However, grown up only. It is possible to see this tree in streets of many largest cities of the world. The group gnetovyh includes the whole collection of the unique persons not similar on one known representative golosemjannyh. Most surprising of them - velvichija, the treelike plant adapted for a life in desert. The most part of its short trunk is hidden in the earth where passes in the powerful and long root similar on lykovatyj a root pasternaka. Two leaves lying flatwise on heated sand of desert grow From a trunk only. And so, these strange plants live till 2000!

Are not less original efedry at which photosynthesis process occurs in stalks similar to a reed that is why leaves are very small and similar on cheshujki. Some kinds efedry can be grown up in gardens of Great Britain, but warmer climate is necessary to the majority. From a plant Ephedra vulgaris receive the important medical preparation - efedrin.