Cyperus involucratus

Umbrella flat sedge

Nonnative to FloridaFISC Category 2

Species Overview

Native to: Eastern Africa, Madagascar, and the Arabian Peninsula

This non-native sedge is grown as an ornamental and has become established in wet, disturbed sites from the central and southern peninsula of Florida. It can spread by dispersal of seeds and rhizomes.

Species Characteristics

Family: Cyperaceae

Habit: perennial, clump-forming sedge with erect triangular stems growing up to 6 ft. tall. It has woody rhizomes from which new stems arise.

Leaves: Stems are topped by a whorl-like cluster of 10-25 long, thin, leaf-like bracts that are from 6-15 in. long. Bracts are not true leaves. Its leaves are bladeless sheaths encasing the stem at the base.

Flowers: 15-25 stalked spikelets arise from the bracts, start as green but turn reddish-brown as they mature. Bloom from summer to fall.

Fruit/Seeds: small, dark brown, ellipsoid, 3-angled nutlets

Distribution in Florida: across the peninsula

Impacts

Established and problematic in environmentally sensitive areas across the Pacific Islands, Australia, New Zealand, and tropical Asia.  In the SE US, it invades disturbed and natural wetland areas.

Control Methods

Preventive Measures

Do not plant.

Cultural/Physical

Remove all plant material including roots.

Mechanical
Biological

No known biological control agents.

Chemical

More research is needed, contact your local IFAS Extension office for assistance with management.

Learn more about this species

UF IFAS Assessment of Non-Native Plants in Florida’s Natural Areas

Atlas of Florida Plants

EDDMapS

USDA Plant Database

Pacific Island Ecosystems as Risk (PIER)

View records and images from University of Florida Herbarium