Equisetum sylvaticum : Woodland Horsetail

Taxonomy

Scientific Name:

Kingdom: Plantae

Division:

Class: Equisetopsida (Horsetail class)

Family: Equisetaceae (Horsetail Family)

Genera: Equisetum (Horsetails) (Lat. equis = horse + seta = hair, alluding to the resemblance of some species to a horses' tail.)

Species: sylvaticum (Lat.: of the woodlands)

English Name(s):

Woodland Horsetail,

First Nation Names:


Description

Structure:

  • Branches in regular whorls (circles) 4-5 ridged, usually branched again.
  • Fertile stems 3-4mm diameter, brownish and pale in spring, later becoming green and producing whorls (circles) of branches like the sterile stems.
  • Stems deciduous, of two types: sterile and fertile, both upright from dark creeping underground stems.
  • Sterile stems 15-35cm tall, 1-5mm diameter. Ridges 10-18 each with 2 rows of tiny bumps. Central cavity over half the width of the stem.

Leaves:

  • All Horsetail (Equisetum spp..) leaves are reduced to circles of scales, united to form sheaths at the stem nodes.
  • Sheaths 3-12mm long, flaring upwards, green, whitish or reddish-brown, the teeth 2-10mm long, often fused into 3-4 broad lobes.

Reproductive Parts:

  • peduncle (spore cone stem) much longer than uppermost stem sheath.
  • Strobili (spore cones) 1-3cm long, soon withering.

Seed:

  • Spores round, each with 4 elaters (spirally-wound filaments) that aid in dispersal.

Not to Be Confused With:

  • Not easily confused with other Horsetails (Equisetum spp.), as Woodland Horsetail (E. sylvaticum) is only Horsetail with branched (forked) branches.

Biology

Physiology:

  • Horsetails (Equisetum spp.) bioaccumulate zinc.
  • The elaters (4 spirally-wound filaments) of each spore respond to humidity by expanding suddenly and throwing the spore out of the strobilus (cone).

Life Cycle:

Seasonal Cycle:

  • Deciduous stems.
  • Spores mature and are released in May/June.

Ecology

Animal Uses:

  • Favorite food of geese and other waterfowl.
  • Horses reported to eat the plant. Possibly eaten by muskrat as well.

Habitat:

  • Moist sites in woods, heathlands and meadows, usually below treeline.

Uses

Modern:

Industrial:

  • Plants used for dyeing yarn. This is done by layering wool or yarn with Horsetail (Equisetum spp.) with about a 10:1 ratio of Horsetail:yarn, then boiling 30 minutes and drying in the shade.

Medicinal:

  • Green plants, because of their silica content, are used for eye treatments and skin disorders.
  • Sterile plants can be used to make an infusion that is said to be effective in combating offensive odour.
  • They are also taken internally, 1 mouthful 4 times daily, to relieve painful or difficult urination or bleeding of the stomach or intestinal tract.

Food:

  • Sterile stems are dried, ground to a powder and used for thickening or to make a mush.
  • This powder has also been used to make a tea and is sold in some grocery stores.

Traditional Gwich'in:

Folklore:

    Industrial:

      Medicinal:

        Food:

          Traditional Other:

          Folklore:

          • The Aleut fed a decoction of these plants to a hated guest as a magical poison.

          Industrial:

            Medicinal:

            • A decoction of the stalks is said to be calcium-rich and and was once considered beneficial as a hair-wash, or, if taken as a tonic, good for fingernails and teeth.
            • Ash of the stems of horsetails (Equisetum spp.) was used alone or with grease as a poultice on burns or sores.
            • Bruised stems were used as a poultice for treating blood poisoning and to stop the swelling of eyelids.
            • Plant decoction was used as a contraceptive, to initiate abortion, to stimulate menstruation and to relieve bladder problems.
            • Roots were heated and placed against aching teeth.
            • Sterile stalks were used as an astringent to stop the spitting of blood.

            Food:

            • Underground stems and roots are collected in the spring by water and are sweet and juicy then, much relished as the first fruit of the season.
            • Underground stems and roots are food to some native groups. They are eaten raw, with or without lard, and are sometimes put in Indian ice-cream.

            Images

            Sterile plant


            Whorled, forked branches


            Strobili (spore cones)


            More strobili (spore cones)


            Illustration from: Illustrated Flora of BC


            Range Maps

            World Range: Circumpolar, In NA from S. Greenland to Alaska. South to Washington, Michigan, Virginia.

            Prov/State Abrev. List


            In Yukon: Found northward to the valley of the Porcupine River.

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