Scouring rush is native to several parts of the world, including Eurasia, Canada, and the United States. Equisetum gets its name from the Latin equus meaning "horse" and seta meaning "bristle" or "animal hair." This rhizomatous, bamboo-like evergreen perennial usually occurs in damp or wet places such as riverbanks, wet meadows, marshes, and woodlands. Growing 3 to 5 feet tall, the plants are easily recognized by their hollow, segmented, rough surface with ashy gray bands marking the segments. The stems can be up to one-half inches in diameter at the base, but they narrow down as they extend upward from the ground. Early in the growing season a whorl of almost unnoticeable scale-like leaves clasps the stem at each node, but these leaves are usually shed as the season progresses.
Horsetail rush is a non-flowering plant. Even though we call this equisetum "scouring rush," it is not a rush at all. Nor is it a fern. It is the only surviving genus of primitive vascular plants that have been found in fossil records dating back to more than 350 million years. We call them fern allies because they are non-flowering, seedless plants that reproduce by spores. Spores are produced in sharp-pointed cones (strobili) about one-inch long on the tips of fertile stems.
The giant equisetums went the way of the dinosaurs but can be found in fossil records, and they are a constituent in the coal we use for fuel. The ones with which we are familiar are much smaller. A handy key can be found in the internet for those interested in identifying the different species.
Grow horsetail rush in full sun to part shade. Although it tolerates a wide range of soils, it grows best in medium to wet places and can even grow in up to four inches of standing water. Gardeners are urged to grow this very aggressive plant in containers to restrain its creeping rhizomes. Once it becomes established it is almost impossible to eradicate. Even a tiny piece of rhizome left in the ground will generate a new plant.
Because of the high silica content in the stems, early Americans made use of them in their daily lives. As a matter of fact, early settlers planted scouring rush and soapwort (Saponaria officinalis) at the edge of a nearby stream. With the silica-filled stems of the scouring rush and the sudsy roots of the soapwort, they had what they needed for cleaning their pots and pans.
Clarinet players sometimes use an equisetum called "Dutch rush" to make reed adjustments. Although this equisetum is available for purchase in music stores, a bit of specialized knowledge about how to use it is needed. Special aging and curing is required before it is usable. Extensive directions about how to prepare and use it as a reed-fixing tool are available on various websites.
Medical uses have been made of the plant. Native Americans used it to stop bleeding, and more recently it has been found to be an effective diuretic. Plants are somewhat toxic to livestock and should be removed from areas where they graze.
The attractive stems are of interest to floral designers who use them in floral designs. Many designers grow it in their gardens so that the stems are always available. Stems dry well and can be purchased in bundles at markets where floral supplies are sold.
According to expert Earl J.S. Rook, most of the equisetums can be found in two main subgenera:
1) Equisetum subgenus hippochaete, the scouring rushes, which include Equisetum hyemale (tall scouring rush), E. laevigatum, (smooth scouring rush), E. scirpoides (dwarf scouring rush), E. variegatum (variegated scouring rush) and
2) Equisetum subgenus equisetum, the horsetails (mostly unknown in North America), which include E. arvense (field horsetail), E. fluviatile (water horsetail), E. palustre (marsh horsetail), E. pretense (meadow horsetail), and E. sylvaticum (wood horsetail). In addition, two hybrids are known: E. ×ferrissii and E. ×mackaii. The GRIN website adds E. telemateia, E. ×nelsonii, and E. ramosissimum to the list. In all somewhere around 20 species have been identified (depending on the authority consulted), and almost anywhere in the world a species can be found.
Because of the aggressive nature of equisetum, many find reason to remove it from their property. Guidelines for its management and information on controlling the plant can be found on Texas A&M University's website.
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AT A GLANCE
Scientific Name: Equisetum hyemale
Pronounce: ek-wis-SEE-tum hy-EH-may-lee
Common Name: tall scouring rush, scouring rush, horsetail, horsetail rush
Hardiness: USDA Zones 4-9
Native Range: Eurasia, North America
Height: 2 to 4 feet
Spread: 1 to 6 feet
Sun: Full sun to part shade
Water: Medium to wet