Evolutionary history of plants seed model is shared by basically all gymnosperms (literally: "naked seeds"), most of which encase their seeds in a woody cone or fleshy aril (the yew, for example), but none of which fully enclose their seeds. The angiosperms ("vessel seeds") are the only group to fully enclose the seed, in a carpel. Fully enclosed seeds opened up a new pathway for plants to follow: that of seed dormancy. The embryo, completely isolated from the external atmosphere and hence protected from desiccation, could survive some years of drought before germinating. Gymnosperm seeds from the Late Carboniferous have been found to contain
Botanical Garden named after Rostovtsev and a botanical garden was headed by Professor V. G. Khrzhanovsky. When it was built a greenhouse for subtropical plants. At present, on the basis of the botanical garden, summer scientific research and production practice is conducted. Students study there ways of plant reproduction, morphogenesis, as well as technologies of landscape design. Periodically free excursions are organized for all comers. In the botanical garden there are landscapes, ornamental and experimental sites, as well as a greenhouse with an area of about 400 m². According to data for 2012, in the botanical garden there are about 600 species and forms of