Common Name: Flowering Rush

General Information

Butomus umbellatus is a
herbaceous, perennial plant producing a cluster of narrow, grass-like leaves up to 150cm tall from a rhizomatous rootstock[].
The plant is harvested from the wild for local use as a food. It is often grown as an ornamental in water gardens.
The plant has become naturalized as a weed in N. America[]. It can displace native riparian vegetation, and can be an obstacle to boat traffic. Once established, populations' increase and can persist indefinitely[].

Known Hazards

None known

Botanical References

,

Range

Temperate Eurasia - Norway to Spain, east to the Russian Far East, China, northwest India; N. Africa - Morocco to Tunisia

Habitat

Pond margins, ditches and canals, avoiding shade[, ]. Plants can tolerate water as deep or deeper than 2 metres, extending to the deepest range of emergent marsh species[].

Properties

Weed Potential	Yes
Edibility Rating
Habit	Perennial
Height	1.00 m
Pollinators	Bees, Flies, Lepidoptera
Cultivation Status	Ornamental, Wild

Cultivation Details

A plant of the cool to cold temperate zone, where it is found at elevations up to 1,500 metres. It grows best in areas where annual daytime temperatures are within the range 15 - 34°c, but can tolerate 12 - 35°c[]. When dormant, the plant can survive temperatures down to about -25°c, but young growth can be severely damaged at 0°c[]. It prefers a mean annual rainfall in the range 400 - 1,000mm, but tolerates 300 - 1,100mm[].
Requires a sunny position[]. A plant of wet habitats, it succeeds in wet soils and in water up to 30cm deep[, ]. Prefers a pH in the range 5 - 8, tolerating 4.5 - 8.5[].
A very ornamental plant[]. The flowers have a scent of bitter almonds[].

Edible Uses

Tuber - cooked[, , , , ]. It should be peeled and the rootlets removed[]. The root can also be dried and ground into a powder[], it can then be used as a thickener in soups etc, or be added to cereal flours when making bread[]. It contains more than 50% starch[]
.
Seed[, , , ]. No more details are given, but the seed is very small and fiddly to use[].

Medicinal

None known

Other Uses

None known

Propagation

Seed - best surface-sown in a cold frame as soon as it is ripe, it usually germinates in the spring. The seed quickly loses its vitality if it is not kept moist[]. When large enough to handle, prick the seedlings out into individual pots and grow them on in a tray of water in the cold frame, planting them out into their permanent positions in early summer.
Division in spring[]. Very easy, larger clumps can be planted direct into their permanent positions. It is best to pot up smaller clumps and grow them on in a cold frame until they are well rooted before planting them out in the summer.