in botany: A genus of plants belonging to the class iriandriae and order monogynia, and in the natural system arranged under the 48th order, aggregatae. There is hardly any calyx; the corolla is monopetalous, gibbous at the base, situated above the germen; there is only one seed. There are 21 species, only four of which are natives of Britain, the officinalis, the lucida, the rubra, the dioica; of these only the officinalis is useful. The root of this plant is perennial: the stalk is upright, smooth, channelled, round, branched, and rises from two to four feet in height: the leaves on the stem are placed in pairs upon short broad sheaths; they are composed of several lance-shaped, partially dentated, veined, smooth pinnae, with an odd one at the end, which is the largest: the floral leaves are spear-shaped and pointed; the flowers are small, of a white or purplish colour, and terminate the stem and branches in large bunches. It flowers in June, and commonly grows about hedges and woods.

It is supposed to be the root of Dioscorides and Galen, by whom it is mentioned as an aromatic and diuretic: it was first brought into estimation in convulsive affections by Fabius Columna, who relates that he cured himself of an epilepsy by the root of this plant: we are told, however, that Columna suffered a relapse of the disorder; and no further accounts of the efficacy of valerian in epilepsy followed till those published by Dominicus Panarolus fifty years afterwards, in which three cases of its success are given. To these may be added many other instances of the good effects of valerian root in this disease, since published by Cruger, Schuchmann, Riverius, Sylvius, Marchant, Chomel, Sauvages, Tiffot, and others.

The advantages said to be derived from this root in epilepsy caused it to be tried in several other complaints termed nervous, particularly those produced by increased mobility and irritability of the nervous system, in which it has been found highly efficacious. Bergius states its virtues to be antipatamodic, diaphoretic, emmenagogue, diuretic, anthelmintic. The root in infusion is most effectual, and is usually given in powder from a scruple to a dram: its unpleasant flavour may be concealed by a small addition of sugar. A tincture of valerian in proof spirit and in volatile spirit are ordered in the London Pharmacopoeia.—Cats are very fond of the smell of this root, and seem to be intoxicated by it.