Valerian (herb) particular binding site. Hydrophilic extractions of the herb commonly sold over the counter, however, probably do not contain significant amounts of isovaltrate. Valerenic acid in valerian stimulates serotonin receptors as a partial agonist, including 5-HT which is implicated in the sleep-wake cycle. The chief constituent of valerian is a yellowish-green to brownish-yellow oil present in the dried root, varying in content from 0.5 to 2.0%. This variation in quantity may be determined by location; a dry, stony soil yields a root richer in oil than moist, fertile soil. The volatile oils that form the active ingredient are pungent, somewhat reminiscent
Valerian (herb) catnip. Valerian is unusual in having flowers with "handedness", that is, having neither radial nor bilateral symmetry. Valerian is considered an invasive species in many jurisdictions including Connecticut, US where it is officially banned and in New Brunswick, Canada where it is listed as a plant of concern. Valerian (herb) Valerian ("Valeriana officinalis", Caprifoliaceae) is a perennial flowering plant native to Europe and Asia. In the summer when the mature plant may have a height of , it bears sweetly scented pink or white flowers that attract many fly species, especially hoverflies of the genus "Eristalis". It is consumed as