Butomus

a genus of herbaceous plants of the family Butomaceae. Botanists assign one or two species to the genus. The flowering rush (B. umbellatus), a perennial reaching 150 cm in height, has a thick spreading rhizome, a scape, and linear radical leaves that are trihedral at the base. The bisexual flowers are in umbellate inflorescences. The pinkish perianth is corollaceous and consists of six persistent segments. The multiple fruit has six to nine follicles.

The plant grows in the temperate zone of Eurasia and in North America (where it was imported). It is found nearly throughout the USSR—along shores, in stagnant or slow-flowing waters, and in marshy meadows. It sometimes is encountered as a weed in rich fields. The rhizome, which is rich in starch, is edible. The leaves are sometimes used for weaving. The plants are raised as ornamentals.