EQUISETACEAE, Horsetail Family

Stems erect or decumbent, from rhizomes, ridged and grooved, deposits of silica on the ridges; stomates in the grooves in definite rows, in bands, or scattered; leaves small, united except at their tips, forming sheaths at the nodes, the free tips persistent or deciduous; sporophylls in cones, each sporophyll with a stalk and a peltate top beneath which several sporangia are borne.