|Scientific name:||Equisetum fluviatile L.|
|Synonym name:||Equisetum limosum L.|
|Swedish name:||Sjöfräken, dyfräken|
|German name:||Teich-Schachtelhalm, Schlamm-Schachtelhalm|
|English name:||Water horsetail|
|Plant Family:||Equisetaceae, Horsetail family, Fräkenväxter|
|Life form:||Herbaceous perennial, creeping rhizomes, often with deep roots.|
|Stems:||Erect dark green stems 2-8 mm in diameter, smooth, with about 10-30 fine ridges. At each joint, the stem has a whorl of tiny, black-tipped scale leaves 5-10 mm long; 80% of the stem diameter hollow; ertile and sterile stems look alike.|
|Leaves:||At each joint, the stem has a whorl of tiny, black-tipped scale leaves 5-10 mm long|
|Flowers:||No flowers; instead, cone-like spore-producing structures develop at the ends of the fertile stems; cones are yellowish-green, 1-2 cm long and 1 cm broad, with numerous scales in dense whorls.|
|Flowering Period:||June, July|
|Fruits:||Produces spores instead of fruit|
|Habitat:||Shallow water, marshes, bogs, and streams|
Derivation of the botanical name:
Equisetum from the Latin equis, "horse" and seta, "bristle".
Equisetum is a primitive plant, a descendat of huge trees that lived in the Paleozoic era (542–251 million years ago).
It produces two different stalks. One is the fertile "joint-grass", the other is the sterile "horse-tail". The fertile stalk produces a cone-like structure at the top, which is covered with spore-producing scales.
fluviatile, of or belonging to a river.
limosum, of marshy or muddy places.