Valerian is a hardy perennial flowering plant, with heads of sweetly scented pink or white flowers. Note that this "sweet" smell is quite overpowering when the flower is placed into a vase. Valerian has uses in herbal medicine as a sedative. It has in the past been recommended for epilepsy but that has not been supported by modern research. The main current use of valerian is as a remedy for insomnia. Large doses are known to cause withdrawal symptoms when stopped, as it is mildly addictive. Those with liver disease are advised not to use valerian. Valerian is the source of valeric acid. An unusual feature of valerian is that the dried root affects the domestic cat in a similar way as that of catnip. If valerian root is left in a place to which cats have access, they will roll in it, drool on it, and chew it. However, some cats won't go near valerian root.