Teena Agrawal
Gymnosperms are the plants always of the great evolutionary values. They have the great empire during the Mesozoic era, as the dawn of the era one can observe the tremendous kind of the decline in the vegetation. However in recent era only the cycadales (apart from the coniferales) are the living representatives of the groups. They are at the lines of the extinction. Only 11 genera of the order are reported from all over the world. In this review articles we are trying to analyze the some of the aspects of the genus Dioon. This is well distributed in the Mexico region (Native place) of the world. A long belt of the Dioon species can be seen over there, however due to change in the climate & other anthropogenic factors the rapid decline can be seen in the vegetation of the species of the Dioon genera in the mountainous region of the Mexico. Conservation strategies are required for the saving of the plants nationally as well as the internationally.