Sedges

207. Sedges

Cyperus spp.

    

A large group of plants which are usually perennials, with stems triangular in cross-section. Leaves are long and thin and often clustered around the base of the stems. Flower heads are either in dense clusters or on short stalks at the end of the stems.

Sedges are widespread in all districts. Some species of Cyperus are major weeds, not only in Australia but throughout the world. Illustrated here is Cyperus iria.

 
 

208. Mullumbimby couch

Cyperus brevifolius

  

A perennial grass-like plant growing to about 15 cm with creeping underground stems. Leaves are shiny, green and about 3 mm wide. Flower heads are elongated knoblike, sometimes 3 lobed and about 9 mm across and are pale green in colour. They are surrounded by about three green leaves and are carried on stiff slender three cornered stalks above the leaves. There are about 100 seeds in each head.

Mullumbimby Couch is widespread throughout coastal areas and is a weed of damp, shady and disturbed situations. It is only a minor weed of cane fields.

 

209. Bunchy sedge

Cyperus polystachyos

  

A tufted and fibrous-rooted perennial, growing usually to 30 cm and occasionally to 60 cm. Leaves grow from the base of the plant and are much shorter than the stems, often only 15 cm long. Flower heads are dense clusters of pale brown, flattened, torpedo-shaped spikelets. These spikelets are 1 to 2 cm long and 2 mm wide. The whole flower head is subtended by 2 to 4 leaf-like outgrowths.

Bunchy Sedge is one of the most widely distributed sedges in Queensland. It favours disturbed sites and is common on road-sides and headlands after grading and reconstruction.

   

210. Nut grass

Cyperus rotundus

    

A perennial, grass-like plant, growing to about 30 cm high, with underground runners and tubers. The tubers are egg shaped, about 12 mm long and covered with dark brown skin. The leaves are bright green and in a cluster at ground level. They are 7.5 to 12.5 cm long, narrow and tapering to a point. Flower heads are on single, thin, three-cornered stalks bearing, at the top,, 2 to 4 green leaves and 4 to 5 branches of varying length. Each branch carries a cluster or slightly-branched cluster of flattened little spikes. Seeds are rich red-brown in colour.

Nut Grass is common in all cane growing districts. It is a persistant and hard-to-control weed. Cultural control is poor because new plants grow successfully from individual tubers ('nuts') when underground runners are broken up.

    
   

211. Rushes

Juncus spp.

    

Perennial plants, growing to about 45 cm with clumps of stiff upright stems. Sheathing leaves surround the bases of the stems. Flower heads grow out from the stems some distance be-low the tips. These are often pale brown in colour and made up of many small flowers, each about 2.5 mm across.

Rushes are widespread in all districts and inhabit wet or badly drained sites. Although usually confined to permanently wet areas they can tolerate dry conditions and will invade cane fields which are temporarily wet because of poor drainage.