Vascular – Exotic
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
Floating grass forming dense mats, with typical two-pronged lowerheads produced in summer
Locally common in the North Island but also in the South Island as far south as Canterbury.
Still and slow flowing water bodies and wetland margins.
Creeping, perennial, mat-forming grass, the stems sprawl along the ground and then grow to 60 cm tall. Stolons long, rooting frequently, with rhizomes. Leaves are distantly alternate, the lamina is 4-10 cm long and 2-6mm wide, tip pointed, bluish-green, soft and lax, slightly hairy above and below, rolled and hairy at base. Ligule up to 4 mm, membrane-like, whitish-translucent, often torn. Auricle absent. Sheath with reddish-purple tinge. Seedhead of 2 (sometimes 1 or 3) diverging, erect racemes, 25-50 mm long; with softly hairy spikelets.
Kikuyu grass (Pennisetum clandestinum). Differs from Mercer grass in that Kikuyu grass lacks a membranous ligule and has a short flowering head that is almost enclosed within the leaves. In contrast, Mercer grass has a very distinctive forked flowering head.
November, December, January, February
Perennial. Reproduces by seed and stem fragmentation. Seeds freely, seed viability unknown. Dispersed by water, livestock pelts and hooves (possibly seed in dung). Contaminated diggers and dumped vegetation.
Reason for introduction
Forage grass for wet areas
Not usually controlled in New Zealand, but may be controlled by mowing or herbicidally.
Tolerates wet, hot to mod-cool, wind, damage and grazing, most soils. Intolerant of frost, deep shade and dry conditions.
paspalum: The Greek name for millet
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).
References and further reading
Champion et al (2012). Freshwater Pests of New Zealand. NIWA publication. http://www.niwa.co.nz/freshwater-and-estuaries/management-tools/identification-guides-and-fact-sheets/freshwater-pest-species.