Horsetails

Terrestrial perennial plants with creeping subterranean rhizomes, roots borne in whorls at the nodes. Aerial stems erect, green, hollow, jointed, conspicuously ribbed,with whorls of branches at the nodes.the branches themselves also jointed. Leaves reduced to a many-toothed short sheath at each node. Cones (sporangiophores) borne at the ends of the main vegetative stems and rarely the branches too.