Cyperus exaltatus

tall flatsedge

 

Cyperus exaltatus

Retz. 1788

pronounced: sy-PEE-russ eks-al-TAH-tuss

(Cyperaceae — the sedge family)

 

common names: tall flatsedge, giant sedge

native 4Cyperus is from the Greek κυπειρος (kypeiros), a sweet-smelling marsh plant; exaltatus is Latin for very tall.

This is a widespread and robust tussock-forming sedge growing in all Australian states in the shallows of streams and lagoons. It also grows in tropical Africa, and in east Asia from China and India through to New Guinea. It is found growing in full sun to 50% shade in water up to about 50 cm deep from the coast to inland areas. It will tolerate both inundation and frost.

It is perennial, and grows from short rhizomes in water and mud to a height of about 2 m. The stems and foliage are light green.

The leaves have a purplish brown sheath at the base, about as long as the flowering stems or longer. They are 3-15 mm wide, flat, with rough edges.

The spikelets are 4-18 mm long, 1-2 mm wide, yellow to brown, with no petals, in open umbels subtended by 3-6 leaflike bracts at the tops of the flowering stems. Each ray of the umbel is composed of spikelets arranged in spikes. There are 5-10 primary branches. There are 3 stamens, and the style is trifid.

The nut is trigonous, ellipsoid, less than half as long as the glume, and yellow-brown in colour.

The plant is recommended for erosion control on dam and creek banks, and provides a good bird habitat.

Cyperus exaltatus is easily confused with Cyperus imbricarus, but its spikes are less dense and peduncled, and the glumes more closely imbricate.

In parts of Asia the plant is harvested from the wild for local use as a medicine, and a source of material for making mats, thatch and the like. The plant is also burnt to make a vegetable salt. The rhizome is grated and eaten. The grated material is also used to make a poultice that is applied to whitlows and other infections in order to draw the pus. Combined with the stem of sugar cane (Saccharum officinarum), it is applied to swollen breasts in order to promote milk flow.

 

Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.
 
Photographed in Nelly Bay 2010, 2013
Page last updated 7th December 2018