The Branched centaury (Centaurium tenuiflorum) belongs to Gentianaceae (the Gentian family). It is an annual herb that is native to the Mediterranean coast of Western Europe. In Europe, it is a weed in fields, and naturalization has been confirmed in Japan as well. It grows along waterways and wetlands and is 20 to 40 cm tall. The basal leaves are almost absent during the flowering season, and the cauline leaves are obovate to elliptic, pointed at the tip, and petiolate. From June to August, the plant produces compound cymes at the top of the stem and produces pink to red flowers about 1 cm in diameter. The corolla has five lobes. It is similar to "European centaury" (Centaurium erythraea), but the sepals are more than two-thirds the length of the flower tube. In "European centaury", the sepal is only about one-third as long as the flower tube.