Family: Equisetaceae
Species: Equisetum hiemale L.
Common name: Winter Horsetail English: Rough Horsetail, Dutch Rush-German: Überwinternder Schachtelhalm
Etymology
The genus name comes from the Latin words Equus (“horse”) and saeta (“silk”), meaning “horsehair,” referring to the appearance of the stems. The species name hiemalis is Latin for “winter” because its stems persist even in winter.
Description
A robust and hardy perennial aquatic plant, E. hiemale consists of thick, erect, hollow, green stems with brown bands at each internode. Its black, underground, creeping rhizomes give rise to these dark green stems, which are generally unbranched. The stems are also very rough due to abundant short, stiff hairs containing silica arranged along the ribs. These “straws” can exceed 1 cm in diameter and reach 1 m in height.
Unlike flowering plants, E. hiemale—similar to ferns—does not produce flowers. Instead, it propagates vegetatively or via spores. In summer, fertile stems (like the sterile ones) develop brown, oval-shaped strobili containing spores at their tips. The plant is entirely frost-hardy and retains its green colour throughout the winter.
Habitat
Native to North America, Europe, and northern Asia.
Properties and Uses
In the past, E. hiemale was more widespread than it is today, and its stems were once employed for their abrasive properties in cleaning wood and copper.
Notes and Curiosities
E. hiemale is an ancient species that has existed on Earth for over 300 million years. Fossilised specimens have been found in rocks dating back to the Silurian period.
It can absorb excess water nutrients, helping keep its habitat clean and healthy. It is typically grown in water or moist soil and should be watered regularly. It also supplies oxygen to the water, benefiting fish and other aquatic animals.
In the Heller garden, it can be easily spotted along waterways. Its sturdy green stems form dense stands that create a natural, calming pond atmosphere. Retaining its dark green colour all year round, it remains an elegant feature for visitors to admire.