Cyperus brevifolius Rottb.
Kyllinga brevifolia Rottb.
Tropical regions of Australia
This is a slender perennial (living greater than 1 season) sedge. Usually around 15cm high however in moist places can grow to 30+ cm high. This plant has very long slender creeping pink/brown rhizomes (underground stems) with roots below every stem.
Leaves are shiny green, 1-2mm wide and channeled. Stems, which normally bear only a single inflorescence (flowerhead), are triangular in cross-section and smooth. Rarely, one stem will bear 1 or 2 subsidiary flowerheads as well.
Inflorescence or spikelet (flowerhead) is a green and egg-shaped, with around 100 tiny flowers per head. The flowerheads protrude above the plant. The leaves are considerably shorter than the stems. The name brevifolius means short-leaved.
Fruit is a tiny nut with both surfaces being convex. Each nut is pear-shaped to elliptic and yellow-brown in colour.
This plant spreads easily under quite dense vegetation and does not respond to herbicide. It usually grows in moist locations not suitable for herbicide use and therefore requires hand removal being sure to removal all rhizomes.
Other plants easily confused with this plant
C. brevifolius is easily confused with C. sphaeroideus, a native of eastern NSW, and C. sesquiflorus originally from tropical Australia. C. sphaeroideus has a yellowish inflorescence (flowerhead) with normally less than 50 flowers per head and is an annual species. C. sesquiflorus has 2 smaller spikes at the base of 1 longer one and the flowerhead is white to very pale green, the plant has either no rhizome or just a very short one.
Sources & References
"Weeds - an illustrated botanical guide to weeds of Australia" by B. A. Auld and R. W. Medd
"Field Guide to Native Plants of Sydney" by Les Robinson
"Plantnet FloraOnline" (2005) http://plantnet.rbgsyd.nsw.gov.au/
Prepared by Justin KY Chu, July 2005
Checked by IEWF, March 2006