They may be growing in your garden or a nearby wildland, but no matter where they are, horsetails will forever be living fossils.

Horsetails have two phases, the fertile phase at right where smooth rods are topped with sporangium and the infertile rods with their whorls of bottle-brush shaped leaves.
A living fossil is a plant that has changed little for millions of years. Horsetails remain virtually identical in all but size to their prehistoric ancestors. They are given their very own family with just one genus, Equisetum. The plants look like bamboo stalks but grow more like reeds. They are too primitive to bear seed so they reproduce by spores like ferns.
The horsetail sporangim that contains microscopic spores at the top of the fertile rods.
Horsetails are lovers of low marshy ground where they spread by a vast network of underground roots into dense colonies wherever there is perpetual moisture.

Much like bamboo, the segmented horsetail rod finds its strength through silica rich cell walls that give it rigidity and an abrasive surface.
Touch their rough stalks to feel how much silica is integrated into their cell walls. Native Americans flattened these out into sand paper-like strips to hone arrow shafts. Pioneers bundled chunks of them into scrub brush, hence their common name, scouring rush. In Medieval times the European species were called pewterwort because the abrasive surface would shine pewter implements without scratching the soft surface.
While horsetails make great water garden plants, beware their spreading nature in the garden. They will travel aggressively. Modern designers use them to fill out long, narrow poorly drained planters for rod-like hedges given a blunt hair cut. To enjoy this strange and wonderful plant, grow in pots without drainage holes, which can be set on porch, patio or in planting beds. The pot can also be buried up to the rim to make it appear more natural.
You can buy Equisetum hyemale online at Digging Dog Nursery:
http://www.diggingdog.com/pages2/plantpages.php/g-0071
