Valerian

I knew nothing about this little plant until I consulted Dr Google and Prof Wiki. Here are a few extracts from Prof Wiki which may amuse you.

Valerian has been used as a medicinal herb since at least the time of ancient Greece and Rome. Hippocrates described its properties, and Galen later prescribed it as a remedy for insomnia. In medieval Sweden, it was sometimes placed in the wedding clothes of the groom to ward off the "envy" of the elves. In the sixteenth century the Anabaptist reformer Pilgram Marpeck prescribed valerian tea for a sick woman.
Few adverse events attributable to valerian have been reported. Large doses may result in stomach ache, apathy, and a feeling of mental dullness or mild depression. Because of the herb's tranquilizer properties, it may cause dizziness or drowsiness, effects that should be considered before driving or operating heavy or hazardous equipment.

And finally......


Preparation


Valeriana officinalis
The chief constituent of valerian is a yellowish-green to brownish-yellow oil which is present in the dried root, varying from 0.5 to 2.0 percent, though an average yield rarely exceeds 0.8 percent. This variation in quantity is partly explained by location; a dry, stony soil, yields a root richer in oil than one that is moist and fertile. The volatile oils that form the active ingredient are extremely pungent, somewhat reminiscent of well-matured cheese. Though some people remain partial to the earthy scent, some may find it to be unpleasant, comparing the odor to that of unwashed feet. Valerian tea should not be prepared with boiling water, as this may drive off the lighter oils.

Valerian blooms large.