ABSTRACT
Eyebright is a small, annual plant with deeply cut leaves, native to the heaths and pastures of Britain, the European continent, and subarctic regions of North America. Similar to several genera of the Scrophulariaceae, Euphrasia is hemiparasitic; the roots have foodgathering nodules that attach to the roots of surrounding plants in order to obtain food. Therefore, it is difficult to cultivate, and virtually the entire supply is harvested from the wild, with little attention to species differences. From July to September, it displays many small, white or purplish flowers variegated with yellow. The various spots and stripes on the flowers cause them to resemble bloodshot, or similarly afflicted, eyes. This, in turn, has caused the plant to be used since the Middle Ages to treat such conditions.2 The usage was obviously based on the so-called "Doctrine of Signatures."
