Equisetum praealtum

Equisetum praealtum
Equisetum praealtum by the Columbia River at Spanish Castle, Douglas County, Washington
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Subclass:	Equisetidae
Order:	Equisetales
Family:	Equisetaceae
Genus:	Equisetum
Subgenus:	E. subg. Hippochaete
Species:	E. praealtum
Binomial name
Equisetum praealtum Raf.
Synonyms [1]
Equisetum hyemale var. affine (Engelm.) A.A.Eaton Equisetum hyemale subsp. affine (Engelm.) Calder & Roy L.Taylor

Equisetum praealtum, ^[1] the scouringrush horsetail, ^[2] is a species of Equisetum (horsetail) native to North America and northeastern Asia. ^[1] It was formerly widely treated as a subspecies or variety of the European and west Asian species Equisetum hyemale (rough horsetail), and still is by some authorities. ^[3]

Description

It is an evergreen herbaceous perennial plant, with green stems, each stem usually topped by a spore-bearing strobilus. The stems, produced in late spring and dying down a year and a half or two years later, are 18–150 cm (7.1–59.1 in) (occasionally to 220 cm (87 in)) tall and 6–18 mm (0.24–0.71 in) diameter, usually unbranched; they are ridged, with 14–50 ridges, and bear whorls of blackish bracts. The young stems are produced in spring and develop an apical spore-bearing strobilus in summer; sometimes, in the second year, the stem will produce a few side branches tipped with further strobili. It also spreads by means of rhizomes, which form clonal colonies. ^{[3] [4]}

Habitat

It is found in wet places, including roadside ditches, along rivers, lake shores, and in wet woods. ^[3]

References

1. "Equisetum praealtum Raf". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2024-09-18.
2. "Equisetum hyemale L. var. affine (Engelm.) A.A.Eaton". USDA Plants Database. Retrieved 2024-09-18.
3. Flora of North America: Equisetum hyemale subsp. affine
4. "Equisetum hyemale affine". Illinois Wildflowers. Retrieved 2024-09-18.