Equisetum scirpoides Michx.
Dwarf scouring rush prefers moist soil, and partial or full sunlight. It often occurs tundra, in mossy hummocks in swamps with northern white cedar (arborvitae), and in cool hardwood and hemlock-hardwood forests, and occasionally in more open calcareous seepy habitats
Plants: These are the smallest of the horsetails, often occurring in low, twisted, tangled-looking mats, intertwined with mosses and grasses, and easily missed. Plants are 1-8" (2.5-20 cm) tall. Stems are unbranched, but thin enough to look like branches of other horsetails. Fertile and sterile stems are evergreen, with six broad ridges. They occur together and look almost identical, except that the fertile stems are a bit more erect, and tipped by a small black conelike structure; while the sterile stems are more curved and unstructured. Stems have a central hollow less than a third of the diameter, smaller than most horsetails.
See Equisetum for a comparison chart.
Leaves: Non-photosynthetic leaves are in thin sheaths of three (rarely four), black or dark brown in color, wrapped around the narrow stems. The sheaths have a white edge.
Fruits: Fruits are a narrow conelike structure called a strobilus, appearing at the tip of each fertile stem. Each “cone” is ¹/₁₆-⅛" (2-5 mm) long. Spores are released from July to August, or the cones may persist during the winter, releasing spores in the spring. The tiny spores have four spirally wound elaters, which aid with dispersal.
Edibility: Dried sterile stems have been used as a thickening agent, or as a tea. Or, according to Aleut folklore, served as a magical poison to a hated guest. Young stems and root systems were prized as first “fruit” of the season by some native peoples.
Medical: A decoction, in addition to serving as both beneficial tea and magical poison, also served as a tonic for teeth and fingernails. And as a contraceptive, a menstruation stimulant, a toothache cure, and for bladder problems. Mixed with grease, it served as a bandage for burns. Sterile stalks served as astringents. If you’re thinking some of these things are entirely contradictory, and hence cannot all be true, well ... so am I.
Equisetum scirpoides at Minnesota Wildflowers
Equisetum scirpoides on inside.ewu.edu (great photos)
Equisetum scirpoides at the Central Yukon Species Inventory Project (more great photos)
Equisetum scirpoides on gobotany.nativeplanttrust.org
Equisetum scirpoides on Wikipedia
Equisetum scirpoides on newyork.plantatlas.usf.edu
Equisetum scirpoides description by Thomas H. Kent, last updated 30 Nov 2020.
Range: Zones 1-9: