Field Horsetail, Scouringrush

Equisetum arvense L.

Equisetaceae (Horsetail Family)

▲ young shoots emerging in spring

▲▼ colony of mostly vegetative shoots (fertile shoots are brownish with cone-- center below)

▲ hillside of field horsetail in Alaska

Field Horsetail, Scouringrush: 

·         a native creeping perennial herbaceous gymnosperm, which produces rhizomes and its fruit is a cone

·         has two types of stems, fertile, unbranched stems that look like little brown bamboo sticks growing in colonies in moist soils (6-24” tall)

·         other stem type (vegetative) is shorter, appearing to be more branched, but actually has needle-like leaves arranged in whorls (3-10” tall)

·         toxic to livestock if over 20% in hay—can cause death in horses and cattle

·         prefers moist soils, but can be found in upland, heavy soils in reduced tillage crops, streambanks, pondbanks, roadsides, rangeland, pasture

·         similar species, common scouringrush:

o   has bright green,  mostly unbranched stems growing 6-36 inches tall or more, with dark bands between segments of the stem

o   stems are evergreen

o   found almost exclusively in moist or wet soils along streams, ponds, roadsides