Jointed, furrowed stems, tubular, usually erect. Leafless - the leaves are replaced by toothed sheaths. Some species have whorls of jointed, ribbed, linear green branches. Some common species bear fruiting cones on separate, earlier pale-brown stems. These stems wither and are followed by barren, thin green stems.
Creeping growth habit. Can be invasive and very difficult to eradicate.
More.. Fern Allies: Horsetails
Photographs immediately above: Great Horsetail