Etymology
Equisetum is from the Latin equus, meaning horse, and saeta, meaning bristle; arvense is from the Latin arvum, meaning ploughed, referencing the growth of the plant in arable soil or disturbed areas.
Native Habitat
Forest edges, wet meadows, prairies and swamps.
Garden Uses
Field horsetail is considered a weed in many areas where crops are grown. Since eradication appears hopeless, embracing the beauty of this plant as a ground cover is recommended.
Overview
Field horsetail is an herbaceous non-flowering perennial most closely allied with ferns. It dates back 300 million years and is native throughout the arctic and temperate regions of the northern hemisphere. It is found in open ground including fields, roadsides, stream banks and lawns. Its aggressive network of rhizomes often allow for large stands of the plants and the rhizomes can penetrate soils to a depth of 6 feet, making it difficult to eradicate once established.
Leaves and Stems
Field horsetail has light pink to tan fertile, spore-bearing stems that arise in spring before its more abundant non-fertile green stems appear. The sterile stems usually range in height from 2” to 20”. The ridged stems have a hollow center and tiers of whorled, ascending branches rising from the base of a stem sheath. There are usually 7–14 needle-like, dark leaves less than an 1/8” wide arranged in whorls around the branches.
Flowers
Horsetail is a non-flowering plant that reproduces by spores.
Fruit/Seed
Fertile stems terminate in a small spore producing cone or strobilus. The strobilus is elongated and tapers to an obtuse to rounded tip. White and misshapen spores are unique to this variety of Equisetum.
Animal Associates
Field horsetail is an important component of the spring and early summer diet of black bears.
Ethnobotanical Uses
This plant is used horticulturally to make a fungicide for powdery mildew and blights. It has been used historically in herbal medicines and veterinary uses, and in parts of Asia the spring shoots are eaten as a vegetable.
Garden Location
Library Garden, Performance Hall Garden (see garden map)
Anecdotal Information
This plant is considered toxic for livestock, particularly horses.
Sources
North Carolina Cooperative Extension Service
The Friends of the Wildflower Garden
Plant Profile by Kathy Kling