This perennial is sometimes planted around ponds but becomes almost impossible to remove due to its deep creeping roots. The erect, ribbed green shoots grow 10 to 100 cm tall with spore-bearing cones at the tips. Some species have fine branches giving a feathery appearance, others resemble Casuarina shoots emerging directly from the soil. Horsetails can invade wetlands, arable land and pastures where they are toxic to livestock.