Butomus umbellatus aka Flowering Rush

Butomus umbellatus, also known as flowering rush or grass rush, is a Eurasian plant species and the sole member of the family Butomaceae. Originally introduced as an ornamental plant in North America, it has now become a serious invasive weed in the Great Lakes area and parts of the Pacific Northwest. In its native country of Israel, it is an endangered species due to habitat loss. This rhizomatous, hairless, perennial aquatic plant is characterized by its swordlike leaves, which gave rise to its name derived from the Greek words for "cow" and "cut." It is a deciduous, rush-like plant with narrow, twisted green leaves. During the summer, it produces fragrant, cup-shaped flowers in umbels that are held above the foliage on upright, red-tinted stems reaching up to 1m in height. The flowers are mid- to deep pink and measure 2-3 cm across. With its basal leaves originating from a stout rhizome, Butomus umbellatus can be found in Great Britain, particularly at the Caldicot and Wentloog Levels.