European centaury (Centaurium erythraea) is native to and widespread in Europe, Western Asia and North Africa. This annual, sometimes a biennial, member of the Gentian Family (Gentianaceae) has been introduced into Eastern Australia and the Americas. In the United States it can be found in disturbed places at low elevations on both coasts, but is absent in the central portion of the country.
An erect plant, the European centaury stem is branched and ends in a dense cyme (branched inflorescence in which central flowers open first) composed of numerous, crowded, phlox-like, yellowish to red flowers. The flowers have no pedicels (stalks). The funnel-shaped corolla has five fused petals. The five stamens are attached midway in the corolla tube and the anthers are conspicuously twisted. The superior ovary is one-celled.
European centaury leaves are simple, lance to egg-shaped and entire with three to five nearly parallel veins. The leaves form a basal rosette and there are also several opposite pairs on the stem.
The minute, irregularly angled, honeycombed seeds are contained in a two-valved, slender capsule.
Members of the Centaurium genus are used medicinally, most often as a tea. The phenolic acids and sterols in the plants are employed to reduce fever and treat gastric and liver diseases, among other ailments. The genus name refers to the myth that the medicinal properties of these plants were discovered by the Centaur.
Other colloquial names for C erythraea are small annual centaury and common centaury. A synonym is Centaurium umbellatum. Derived from the Greek “erythro”, the species designation means “red”.
These European centaury specimens were found in July along the Rail Trail at Ankeny National Wildlife Area in Oregon (Marion County).