Equisetum

Equisetum giganteum Expedition - Personal account of a trip to find Giant Horsetails in Costa Rica.
planeta.clix.pt/welwitschia/equisetum/

Equisetum Images - Links to several microscopic images of Equisetum.
bryophytes.plant.siu.edu/diversityweb/equisetum.html

Equisetum x schaffneri - image
www.botany.hawaii.edu/faculty/carr/images/equ_xsc_cu.jpg

Equisetum x schaffneri - image
www.botany.hawaii.edu/faculty/carr/images/equ_sp.jpg

Giant Horsetails - Detailed information about Equisetum giganteum, E. myriochaetum, and E. x schaffneri. Includes photos of wild plants and links.
www.fiu.edu/~chusb001/giant_equisetum.html

Horsetails: Relic Plants from Prehistory - Photographic study by Dave Walker of these plants, including photomicrographs of the cross section of a cone.
www.microscopy-uk.org.uk/mag/artjun99/dwhtail.html

World of Equisetum - Detailed species accounts of the horsetails (Equisetum subgenus Equisetum).
members.eunet.at/m.matus/