Mullumbimby couch

Cyperus brevifolius
Mullumbimby couch
Mullumbimby couch flowering
Mullumbimby couch detail
Mullumbimby couch detail
Grass
Basal
Simple
Brown
Green

A long-lived grass-like plant with long underground runners and upright flowering stems up to 40 cm tall. Its upright stems are three-angled in cross-section and only 0.5-1.5 mm thick. Its bright green leaves (1-3 mm wide) are hairless and sheath the stem at the base. Its pale green seed-heads (6-7 mm long) have three or four green leafy bracts at the base and contain numerous small flower spikelets. Its 'seeds' are yellow to reddish-brown in colour and topped with a small projection 1-1.5 mm long.

Common names 
Also known as: Globe kyllinga, Perennial greenhead sedge, Short-leaf flatsedge,
Family 
Cyperaceae
Deciduous 
No
Flowering time 
Year round
Native/Exotic 
Exotic
Origin 
This species is widespread in the tropical, sub-tropical and warmer temperate regions of the world and its exact origin in obscure. However, some authors believe it to be native to tropical Asia and the warmer temperate regions of China and Japan.
Notifiable 
No
Council declaration 
SIL – Special Investigation List
Known distribution 

This species is very widely naturalised in the coastal and sub-coastal regions of Australia. It is particularly common in the northern and eastern parts of the country (i.e. in the northern parts of Western Australia and the Northern Territory, in south-eastern, central and northern Queensland, in eastern New South Wales and in the ACT).

Habitat 

A widespread weed that prefers damp and shady habitats. It is most commonly found in gardens, footpaths, lawns, roadsides, pastures, disturbed sites and waste areas, but is also a weed of riparian vegetation, wetlands and some crops.

Habit 

A long-lived (i.e. perennial) grass-like plant with long underground runners (i.e. rhizomes) and upright flowering stems 5-40 cm tall.

Impact and control methods 

This widespread sedge is a common weed of habitation (i.e. gardens and lawns), disturbed sites, waste areas and wetter pastures. It has also invaded disturbed wetlands, swamps and creeks, and for this reason it is also regarded as an environmental weed in parts of Western Australia, Queensland, New South Wales and Victoria.

Mullumbimby couch (Cyperus brevifolius) was recently ranked among the 200 most invasive plants in south-eastern Queensland. It also appears on environmental weed lists for the wider Sydney and Blue Mountains region and the Goulburn Broken Catchment in Victoria, and is listed as a moderately invasive species in the Environmental Weeds Strategy of Western Australia.

Stem and leaves 

Plants produce brownish or whitish coloured underground runners (i.e. rhizomes) which send up smooth, hairless (i.e. glabrous) stems that are upright (i.e. erect or ascending) in nature. These upright flowering stems are three-angled in cross-section (i.e. trigonous) and only 0.5-1.5 mm thick.

The bright green and shiny leaves (2.5-12.5 cm long and 1-3 mm wide) are hairless (i.e. glabrous) and have sheaths at the base. These leaves have entire margins and pointed tips (i.e. acute apices), and are clustered towards the bases of the flowering stems.

Flowers and fruits 

The seed-heads (i.e. inflorescences) are pale green, egg-shaped (i.e. ovoid) spikes. These flower spikes (6-7 mm long and 6-8 mm wide) have three or four green leafy bracts at the base and contain numerous densely packed flower spikelets. The flower spikelets consist of a bract (i.e. glume) 1.5-3 mm long and a single tiny flower (i.e. floret). Flowering occurs throughout the year.

The 'seeds' (i.e. nuts or achenes) are egg-shaped (i.e. ovoid), yellow to reddish-brown in colour, and topped with a small projection (i.e. beak) 1-1.5 mm long. They are often enclosed within papery whitish bracts (i.e. glumes).

Reproduction and dispersal 

This species reproduces by seed and vegetatively via its creeping stems (i.e. rhizomes).

Its seeds may be spread by water, animals, mowers or in contaminated soil. The creeping stems (i.e. rhizomes) spread laterally, enabling large colonies to be formed, and may also be spread in soil and dumped garden waste.

Similar species 

Mullumbimby couch (Cyperus brevifolius) is very similar to kyllinga weed (Cyperus sesquiflorus ) and reasonably similar to slender sedge (Cyperus gracilis ). These species can be distinguished by the following differences:

- Mullumbimby couch (Cyperus brevifolius) produces underground runners and has pale green coloured seed-heads. These small seed-heads (6-8 mm long) are very compact and egg-shaped (i.e. ovoid).

- kyllinga weed (Cyperus sesquiflorus ) only grows in tufts and has pale whitish-coloured seed-heads. These seed-heads (6-12 mm long) are very compact and usually have a larger central egg-shaped (i.e. ovoid) spike with two smaller spikes at the base.