Equisetum telmateia
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| Equisetum telmateia | ||||||||||||||
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 Equisetum telmateia
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| Equisetum telmateia Ehrh. |
Equisetum telmateia (Great Horsetail or Giant Horsetail) is a species of Equisetum (horsetail) with an unusual distribution, with one subspecies native to Europe, western Asia and northwest Africa, and a second subspecies native to western North America.[1][2]
It is a herbaceous perennial plant, with separate green photosynthetic sterile stems, and pale yellowish non-photosynthetic spore-bearing fertile stems. The sterile stems, produced in late spring and dying down in late autumn, are 30-150 cm (rarely to 240 cm) tall (the tallest species of horsetail outside of tropical regions) and 1 cm diameter, heavily branched, with whorls of 14–40 branches, these up to 20 cm long, 1–2 mm diameter and unbranched, emerging from the axils of a ring of bracts. The fertile stems are produced in early spring before the sterile shoots, growing to 15–45 cm tall with an apical spore-bearing strobilus 4–10 cm long and 1–2 cm broad, and no side branches; the spores disperse in mid spring, with the fertile stems dying immediately after spore release. Occasional plants produce stems that are both fertile and photosynthetic.[2][3][4]
It is found in damp shady places, spring fens and seepage lines, usually in open woodlands, commonly forming large clonal colonies.[2][3]
There are two subspecies:[1][4]
- Equisetum telamteia subsp. telmateia. Great Horsetail. Europe, western Asia, northwest Africa. Main stem between branch whorls pale greenish white.
- Equisetum telamteia subsp. braunii (Milde) Hauke. Giant Horsetail. Western North America, from southeastern Alaska and western British Columbia south to California. Main stem between branch whorls green.
[edit] References
- ^ a b Germplasm Resources Information Network: Equisetum telmateia
- ^ a b c Hyde, H. A., Wade, A. E., & Harrison, S. G. (1978). Welsh Ferns. National Museum of Wales ISBN 0-7200-0210-9.
- ^ a b Clapham, A. R., Tutin, T. G., & Warburg, E. F. (1981). Excursion Flora of the British Isles, 3rd ed., Cambridge: University Press, 6. ISBN 0521232902.
- ^ a b Flora of North America: Equisetum telmateia
 Equisetum telamteia subsp. braunii, San Jose, California, showing green stem. |
