Typically, after autumn establishment and winter dormancy, the plant grows from a short rhizome to 2 m high, flowers, and then dies back again in the winter. The Valerianaceae, which has about 200 perennial herb and small shrub species throughout the world, is chiefly found in the temperate and cold regions of the northern hemisphere. V. officinalis is indigenous to Eastern and Central Europe, but has become naturalised in Western Europe and parts of North America after early introduction by colonists. Valerian is highly variable. Polyploidy occurs in V. officinalis and there are diploid, tetraploid, and octaploid types.
English valerian is usually octaploid and Central European usually tetraploid.
Valerian is widely used in Europe as a mild sedative and sleep aid for insomnia, excitability, and exhaustion. It has depressant activities on the central nervous system, is antispasmodic, and has been described as having equalising effects - acting as a sedative in agitated states and a stimulant in fatigue. The long standing clinical use of valerian is as a sedative mainly because of the valepotriates present and the volatile oil constituents, notably valerenic acid. Studies have concluded that valerian extracts helped to improve significantly sleep quality of people suffering from mild insomnia, with minimal side effects. V. officinalis preparations are considered safe despite the known in vitro cytotoxic activity of valepotriates and no acute side effects have been reported.