EQUISETUM (from equi, of a horse, and seta, a hair). Horsetail. ORD. Equisetaceae. A genus of leafless herbs, with a perennial, usually creeping rootstock, and erect, Rush-like hollow and jointed stems, marked with longitudinal furrows, with a sheath at each joint, inclosing the base of the next internode. Some of the species of this neglected genus are well worth growing in wet, shady spots, and in similar situations in the rock garden. Increased by division. EQUISETUM maximum (largest). cones large. Sterile stems 3ft. to 6ft. high, twenty to forty-grooved, furnished with whorls of slender, sub-erect branches. Fertile stem stout, about 1ft. high, with many pale-brown sheaths; teeth two-ribbed. Northern hemisphere (Britain). A very fine plant when well grown. SYN. EQUISETUM Telmateia. EQUISETUM sylvaticum (wood).* cones ovoid-oblong, obtuse. Stems ten to eighteen-grooved; branches recurved or deflexed, divided; stem sheaths lax; teeth long, obtuse; teeth of branch sheaths three-ribbed to the top. Northern hemisphere (Britain). A very pretty plant for pot culture in a conservatory. Readily recognised by the elegant appearance of the whorls of compound, recurved branches. EQUISETUM Telmateia (Telmateia). A synonym of EQUISETUM maximum.