Information on Flowering-rush

Common Name: Flowering-rush
Scientific Name: Butomus umbellatus
Irish Name: Luachair dhearg
Family Group: Butomaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period

Click for list of all flowering by month
Flowering-rush is not easily confused with other wild plants on this web site.

Flowering-rush is found at water margins in lakes, ditches and canals. It grows to a height of 1.5m and produces single clusters or umbels of flowers in July and August. The flowers (16-25mm across) have 3 pale to deep-pink, dark-veined petals and 3 smaller, narrower sepals. They are borne on stalks of uneven lengths on leafless stems, with leaf-like bracts below the clusters. The grey-green leaves are long, slender, triangular in cross-section and all arise from the base of the plant. It grows on creeping underground stems or rhizomes and is a native perennial which is not commonly found except in northern areas, Munster and along the river Shannon. It belongs to the Butomaceae or Flowering-rush family.

I first saw and photographed Flowering-rush in Co Donegal while on a holiday near Maghery in the late 1970’s. I have never seen it since. The photograph was taken on old print film and I would love to find this species again and take a newer photo of it. It deserves better. 

If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre

Flowering-rush – which is not a true rush – was introduced into North America where it has become an invasive weed and is causing a lot of problems in the Great Lakes. It was brought in as a pond species but, as only a very small part of the rhizome is necessary to produce a new plant, it has become quite widespread.