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]
| Equisetum praealtum | |
|---|---|
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| Equisetum praealtum by the Columbia River at Spanish Castle, Douglas County, Washington | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | Polypodiophyta |
| Class: | Polypodiopsida |
| Subclass: | Equisetidae |
| Order: | Equisetales |
| Family: | Equisetaceae |
| Genus: | Equisetum |
| Subgenus: | E. subg. Hippochaete |
| Species: | E. praealtum
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| Binomial name | |
| Equisetum praealtum | |
| Synonyms[1] | |
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Description
editIt 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
editIt is found in wet places, including roadside ditches, along rivers, lake shores, and in wet woods.[3]
References
edit
- ^ a b c "Equisetum praealtum Raf". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2024-09-18.
- ^ "Equisetum hyemale L. var. affine (Engelm.) A.A.Eaton". USDA Plants Database. Retrieved 2024-09-18.
- ^ a b c Flora of North America: Equisetum hyemale subsp. affine
- ^ "Equisetum hyemale affine". Illinois Wildflowers. Retrieved 2024-09-18.