Equisetum fluviatile, commonly known as Water Horsetail, is a perennial herb that thrives in wetlands, including marshes, swamps, and along the banks of rivers and lakes in the temperate Northern Hemisphere, spanning from Eurasia to North America. It typically grows to a height of 12-39 inches (30-100 cm) and features hollow, dark green stems that are ridged, with whorls of slender branches at regular intervals. Water Horsetail does not produce flowers but reproduces by spores released from cone-like structures at the stem tips and through aggressive rhizomes, which can contribute to its invasive nature in non-native habitats.

Water Horsetail is valued for its architectural form and prehistoric appearance, often used in water gardens and naturalistic plantings. It prefers full sun to part shade and requires constantly moist or even submerged soil conditions to thrive. While it can be an attractive addition to pond margins and water features, it is important to manage its spread to prevent it from becoming invasive. In cultivation, it can be contained using barriers or planted in pots to restrict rhizome growth.CC BY-SA 4.0