Equisetopsida
The division Equisetophyta is a taxon in the kingdom Plantae containing primitive land plants. Now extinct plant species in this division were among the first plants to grow on land. With the exception of the horsetails Equisetum, all members of this grouping are known only from fossils, and included large trees that grew during the Carboniferous period. There is only one class, the Equisetopsida.