Equisetophyta

Equisetaceae - General description of this family of terrestrial, herbaceous, homosporous vascular plants, comprising a single genus with about 15 species. Includes photos of several Equisetum species.
www.botany.hawaii.edu/faculty/carr/equiset.htm

Horsetails - Equisetaceae - Brief description of the horsetail family, including descriptions of several Equisetum species.
bodd.cf.ac.uk/BotDermFolder/BotDermE/EQUI.html