Despite the perception that the spirit is produced with gentian flowers (which are depicted in the labeling by many producers), Gentian is actually produced using gentian root, most commonly the yellow gentian, which is a larger variety. Less commonly, the roots from other flowers from the Gentian genus are used, such as the purple gentian, brown gentian, or spotted gentian. The harvesting of gentian from the wild is strictly controlled; as a result, fields are planted with the specific purpose of being harvested. In both the EU and Switzerland, the alcoholic strength of Gentian must be at least 37.5 percent alcohol by volume.