Flowering Rush

Butomus umbellatus is a perennial aquatic plant with swordlike leaves, named from the Greek words 'bous' and 'tome' for its leaf shape. It is native to regions such as Europe, Asia, and parts of the Middle East. The species was first described in 1753 by Linnaeus. While it is locally present in places like the Caldicot and Wentloog Levels in Great Britain, it has spread beyond its native range and is now a problematic invasive in North America. Its introduction as an ornamental has led to ecological concerns in areas like the Great Lakes. The plant is characterized by its rhizomatous growth and umbellate inflorescences. The type specimen for this species was not annotated by Linnaeus, and an alternative type was proposed by Dandy, though it is not accepted as original material.