Equisetum scirpoides aka Dwarf Horsetail

Equisetum scirpoides is known as dwarf horsetail or dwarf scouring rush. This evergreen perennial belongs to the horsetail family, Equisetaceae. Its native range spans the northern hemisphere's cold and temperate regions. These include northern North America, Greenland, northern Europe, and parts of Asia. It also grows outside its native range in Britain and Belgium. Wild plants grow in wetlands, woods, bogs, and mossy ground. Some stems lie partly buried in humus.

The plant makes clumps of thin, wiry, upright stems. Garden plants stand about 0.5–1 foot (0.15–0.3 m) tall. RHS describes plants near 0.7 feet (0.2 m). Its broader size range reaches 1.6 feet (0.5 m). Clumps can spread 1–4 feet (0.3–1.2 m) wide. Dark green stems have ridges and clear joints. They lack branches and may bend into zigzags or curls. Tiny black leaves form rings of scales at each joint. The stems stay green through the seasons.

This plant makes neither flowers nor fruit. Fertile stems bear small, pointed cones at their tips. These hold spores rather than seeds. Spores leave the cones in early to midsummer. Some remain through winter and leave the next spring. The plant also spreads through underground rhizomes. Its growth rate is moderate. Division provides a way to raise more plants.

Grow dwarf horsetail in moist or boggy soil. It accepts sun or partial shade, and tolerates deeper shade. Suitable soils include sand, loam, clay, and chalk. It also accepts acid, neutral, or alkaline ground. A pot standing in a water tray suits its needs. Containers help curb its spread into nearby beds. RHS warns that unchecked growth can become a nuisance. NC State lists USDA zones 4–10; RHS gives UK hardiness H4.

Its jointed stems add texture to rain gardens and pond edges. It also suits water gardens, pots, and small groups. Wildlife uses the clumps for cover, and aquatic animals eat it. The rough stems have served as tools for cleaning dishes. Native American groups have also used this plant as food. PFAF records edible roots, root tubercles, and sterile stems. It lists no known hazards, but this does not establish pet safety. RHS reports few pest or disease troubles. It needs no routine pruning.