The Giant Horsetail is a perennial composed of separate sterile and fertile stems with quite different appearances. The green sterile stems, produced in late spring and dying in late fall, are 30-240 cm tall and 1 cm in diameter. The hollow erect, green stem is coated in layered whorls with 14-40 thin, straight branches. The branches, which are up to 20 centimeters long and 1-2 millimeters in diameter, are banded in shades of dark green. The fertile stems, produced in early spring before the sterile shoots, are 15-45 cm tall shoots with no side branches. When the spores are dispersed in mid-spring, the fertile stem immediately dies.
Basic Information
Member of the Equisetaceae family
Perennial herb and fern
There are two recognized subspecies:
Equisetum telmateia subsp. telmateia (Great horsetail) — Europe, western Asia, northwest Africa; main stem is pale greenish white
Equisetum telmateia subsp. braunii (Northern giant horsetail) — Western North America, from southeastern Alaska and western British Columbia south to California; Main stem between branch whorls green
Habitat
Native to Europe, western Asia, northwest Africa, and western North America
Found in oak woodlands, chaparral, mixed evergreen forests, and on shady slopes
Ecological Role
Horsetails absorb silica from the soil, protecting the plants from insect and fungal damage
Reproduction
This is a non-flowering species — rather than produce flowers, this plant releases airborne spores to reproduce
Sporulates in mid-spring
There are separate green photosynthetic sterile stems and pale yellowish non-photosynthetic spore-bearing fertile stems on this plant
Alternative Names
Great horsetail, northern giant horsetail
Historical Uses
The young stems were eaten raw, roasted, or boiled by many tribes including the Clallam, Quileute, Cowlitz, Saanich, Nitinaht, and Kashaya Pomo
The roots and stems were widely used for basket making
The stems were used to polish arrow shafts and canoes
The hollow, water filled stem segments were used by the Nitinaht when water was scarce
Additional Information
Horsetails are often referred to as “living fossils,” as Equisetum is the only remaining genus of the subclass Equisetidae, which were dominant part of understory vegetation in late Paleozoic forests for more than 100 million years