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Products > Equisetum myriochaetum
Equisetum myriochaetum - Giant Horsetail
Image of Equisetum myriochaetum
[2nd Image]
Habit and Cultural Information
Category: Grass-like
Family: Equisetaceae (Horsetails)
Origin: Mexico (North America)
Evergreen: Yes
Flower Color: NA
Bloomtime: Not Significant
Synonyms: [E. mexicanum]
Height: 6-10 feet
Width: Running
Exposure: Sun or Shade
Irrigation (H2O Info): High Water Needs
Winter Hardiness: 15-20 F
May be Poisonous  (More Info): Yes
Equisetum myriochaetum (Giant Horsetail) - This prehistoric remnant is among the tallest of the living horsetails. Given optimum conditions, which includes a frost free location with ample water and rich soil, this subtropical plant is evergreen and can grow to an astonishing 15 feet tall and in some reported cases to 24 feet although plants attaining this height were likely stems supported by other vegetation. From underground rhizomes are produced 1/2 inch wide hollow aerial stems that arise at tight intervals, forming dense colonies. The stems appear jointed with fine hair like green leaves in whorls sometimes accompanied by side branches that both emerge from sheaths at the stem nodes. Plant in full sun to light shade in a rich soil and keep moist. Best in a container or with an area protected by a deep root barrier to check spread of the rhizomes. This species is found in Nicaragua, Costa Rica, Colombia, Venezuela, Ecuador, Peru and Mexico (Nayarit, Jalisco, Colima, Michoacan, Guerrero, Mexico State, Oaxaca, Puebla, Veracruz, Hidalgo, San Luis Potosi, Nuevo Leon, Chiapas). We received our stock on this plant from Monterey Bay Nursery who received it from the University of California, Berkeley - their accession listed it as collected in Veracruz, Mexico. Horsetails show promise as ground covers for dikes, road cuts, abandoned strip mines and other bare areas. They tend to absorb heavy metals, and so may be useful as biological monitors of water or soil contamination by zinc, cadmium and lead. Note, however, that horsetails cause a serious poisoning, called equisetosis, in horses. For this reason it may not be suitable for certain farm ponds. Name origin: 'equus', Latin for "horse" and 'setum', Latin for "bristle".  The information about Equisetum myriochaetum displayed on this page is based on research conducted in our nursery library and from online sources we consider reliable. We will also relate those observations made of this plant as it grows in our nursery gardens and in other gardens that we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone who has additional information, particularly when they share cultural information that would aid others in growing it.