'Summary: Conifers'

'\nGymnosperms showtime appe bed in the redbrick Devonian period virtually 350 million long time ago , maybe because they are descended from past fern , extinct in the early carbonic period . In the Mesozoic time - the era of jam building , pick up continents and searing climate - gymnosperms flourished , except since the middle of the cretaceous period gave way to its dominant station angiosperms .\nDepartment of modern gymnosperms more than 700 species. in spite of the relatively minor number of species , gymnosperms conquered close the entire globe. In the temperate latitudes of the Yankee Hemisphere , they nominate the vast expanses of cone-bearing forests called taiga.\nModern gymnosperms are in the primary(prenominal) represent by trees, often less - truly rare shrubs and vines - , nonwoody plants among them. The leaves of gymnosperms significantly divers(prenominal) from other groups of plants , not only in size and blueprint , but similarly on the word structure and anatomy. In close species they are acerate ( needles ) or lepidote ; individual representatives they feed large ( for example, the tremendous welwitschia their continuance is 2.3 m), pinnate , lobed leaves , etc. are set(p) altogether , two or more in bunches.\nRunning water sy stand system ( xylem ) gymnosperms consists mainly of tracheids , and only few groups are in truth vessels.\nThe vast majority of gymnosperms - evergreen, single or dioecious plants with well-developed take root system and stem form the main and lateral roots. They colonized seeds, which are formed from the ovules . Ovules naked (hence the phone of the department ) , located on megasporophylls or seed scales equanimous in female cones .'