Field Horsetail

Equisetum arvense

Alternate names
Horsetail; Scouring Rush

Weed Description
A perennial with spreading rhizome systems, sometimes mistaken as a grass. Two stem forms are present, an erect leafless cone-bearing stem that emerges in early spring and a later-emerging vegetative, highly branched stem that resembles a horse's tail. Field horsetail is usually found in wet areas.

Leaves
No obvious leaves are present but there are leaves that have been reduced to scales that are whorled around the stem. These scales are dark and toothed (14-20 mm long), and occur at the nodes.

Stems
Green, hollow, and grooved. Stems can grow up to 2 feet in height and are 1.5-5 mm thick.

Flowers
Reproduction is asexual, spores are released from mid-April to May.

Roots
Fibrous roots with an extensive rhizome system that occurs at depths of as much as 4 or 5 feet.

Identifying Characteristics
Scouringrush (Equisetum hyemale) is similiar in appearance but only has the jointed, leafless, unbranched, cone-bearing stems and not the vegetative stems that resemble a horse's tail. Scouringrush is also exclusively found in ditchbanks and other wet areas whereas field horsetail is not always confined to these type of areas.

Office of Programs

University of Missouri

Field Horsetail

Equisetum arvense