Су құрағының гүлі (Menyanthes trifoliata)

Genus of flowering plants

Menyanthes is a monotypic genus of flowering plants in the family Menyanthaceae containing the single species Menyanthes trifoliata. The North American form is often referred to as M. trifoliata var. minor Michx. It is known in English by the common names bogbean and buckbean.

Menyanthes trifoliata has a horizontal rhizome with alternate, trifoliate leaves. The inflorescence is an erect raceme of white flowers. The buds are rose pink in color. The flowers when fully open look like "white stars" and the petals are fringed with white whiskers. The species occurs in fens and bogs in Asia, Europe, and North America. In eastern North America, it is considered to be a diagnostic fen species. It sometimes creates big quagmires with its thick roots.

The name Menyanthes comes from the Greek words menyein, meaning "disclosing", and anthos, meaning "flower", in reference to the sequential opening of flowers on the inflorescence.

One fossil seed of Menyanthes trifoliata has been extracted from borehole samples of the Middle Miocene fresh water deposits in Nowy Sacz Basin, West Carpathians, Poland.

The species is protected in the United States.

The rootstock can be ground into an unpalatable flour for emergency use. The plant has a characteristic strong and bitter taste, which can be used in schnapps. In China, the plant is known as "sleeping herbs" (睡菜) or "herbs that calm consciousness" (暝菜). Guangdong Xing Yu (1678), a Qing dynasty book by Chiu Da Jun, records: "Eat [Menyanthes trifoliata;] makes people sleep well." The Compendium of Materia Medica records: "[Treats] insomnia, restlessness".