Flowering Rush

Common Name: Flowering rush
Scientific Name: Butomus umbellatus
Origin: Central Asia and Europe

Description

Flowering rush is a perennial, herbaceous, aquatic plant that grows 1-4 ft. tall, on an erect stem. The narrow, pointed leaves are triangular in cross section and have smooth edges and parallel veins. The pink flowers have three pink sepals and three petals, that are arranged in clusters, or umbels, of 20-50 flowers. This plant blooms from July to September, and can be difficult to identify without its flowers present. Flowering rush spreads through rhizomes and bulbils.

Habitat

Flowering rush can be found along shorelines and in slow-moving rivers and streams that are up to 9 ft. deep. It grows along shores in shallow water as an upright and stiff plant. In deeper water, it grows beneath the water with the leaves floating on the surface. Submerged plants often don’t flower.

Threat

When water levels drop, flowering rush can quickly establish on newly exposed soil. It can crowd out native plants, reduce open water habitat for some trout and shelters invasive fish species. Dense stands can interfere with recreation.

Management

Small infestations can be carefully dug up, taking care to leave no bulbils behind. Divers using suction dredges have also been effective, but entire rhizomes must be removed without losing the bulbils. Herbicides may be effective when applied during the summer and when waters are calm, or during a dry spell.

Regional Distribution

Locally Common

WNY PRISM Priority

Tier 3 – Containment

Invasive Species Priorities – Tier Chart

Pathways

Flowering rush was introduced to the Great Lakes through ship ballast water and as an ornamental water garden plant.