T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Cyperus brevifolius (Shortleaf Spikesedge) Kyllinga brevifolia

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Cyperaceae
Genus: Cyperus
Species: C. brevifolius
Binomial name: Cyperus brevifolius. (The basionym of this name is Kyllinga brevifolia,
Synonyms: Cyperus cruciformis, Cyperus crypsoides, Kyllinga brevifolia, Kyllinga aurata, Kyllinga cruciata, Kyllinga cruciforis, Kyllinga cruciformis, Kyllinga gracilis, Kyllinga sororia, Kyllinga monocephala, Kyllinga pumilio, Kyllinga rigidula, Kyllinga squarrosa, Kyllinga longiculmis, Kyllinga caespitosa var. robusta, Pycreus pumilus var. substerilis, Kyllinga colorata, Schoenus coloratus, Schaenoides brevifolius,
Common names: Globe sedge, Shortleaf Spikesedge, Mullumbimby couch, Globe kyllinga, Shortleaf spikesedge, Short-leaf flatsedge, Green kyllinga, Perennial greenhead sedge, Kyllinga weed,

Cyperus brevifolius is a long-lived, perennial, invasive species of sedge that is widespread in the tropical, sub-tropical and warmer temperate regions of the world. Its exact origin is obscure. In New Zealand’s North Island, it is scattered in the northern areas and south to Taranaki. It is also found on New Zealand’s northern offshore islands. In the South Island, it is found in Westland.
It inhabits gardens, wet pastures, swamps, creeks, irrigation ditches, heavily trampled/mown areas and it sometimes forms short, dense, extensive swards on damp flats. Since it usually grows in moist locations herbicide use is not suitable and hand removal is needed to remove all rhizomes.

Cyperus brevifolius is a slender perennial, sedge with a long, creeping, slender, rhizome that has reddish-purple scales. There are roots below every stem.
The plant will produce one to several erect stems usually around 15cm high. In some moist areas, it can grow to > 50 cm high.
The leaves are a shiny green and are >3mm wide and 2.5-12.5 cm long. They are hairless (glabrous) and have sheaths at the base. These leaves have entire margins and pointed tips (acute apices) and are clustered towards the bases of the flowering stems.
The stems are smooth and are triangular in cross-section (trigonous)) and bear only a single, egg-shaped (ovoid) spikes >10 mm long. There are about 100 tiny flowers per head. Sometimes (rarely) one stem will bear 1 or 2 subsidiary flowerheads. The flowerheads protrude above the plant. The green to yellow oval flowerhead usually has three (rarely two or four) long grass-like leaves immediately under the inflorescence. These leaves are 1-2mm wide and are channelled longitudinally. There is no other sedge in New Zealand that has the single oval flowerhead subtended by 3 long leafy bracts. 

Flowering occurs throughout the year. The fruit is a tiny yellow-brown, pear-shaped nut with both surfaces being convex. It is topped with a small projection (beak) >1.5 mm long. They are often enclosed within papery whitish bracts (glumes).

Cyperus brevifolius reproduces by seed and vegetatively via its creeping rhizomes. The seeds can be spread by water, animals, mowers or in contaminated soil. The creeping rhizomes spread laterally, enabling large colonies to be formed. Rhizomes may also be spread soil movement and by being dumped in garden waste.

The habit of Cyperus brevifolius

 


A photo of the ovoid flowerhead with only two leaves immediately under the inflorescence. This is rare, usually, they have three.


The inflorescence with about 100 tiny flowers
  

A photo showing the plants leaves and its slender creeping rhizome (underground stem)


Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/