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

Nassella neesiana (Chilean needle grass)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Poaceae
Tribe: Stipeae
Genus: Nassella
Species: N. neesiana
Binominal name: Nassella neesiana
Common names: Chilean needle grass. CNG 

Nassella neesiana is an erect, tufted, perennial tussock in the spear grass group of grasses. It is native to Argentina, Bolivia, Ecuador, Uruguay, southern Brazil and Chile. In New Zealand it was first found in the Blind River area of Marlborough in 1930, probably coming here in grass seed imported from Australia. It then turned up in Hawkes Bay in 1962. It has now turned up in the Auckland region and in 2008 it turned up in Spotswood, North Canterbury but has since has been found in many more north Canterbury sites.

Nassella neesiana has many shoots growing from its base that are <1m high. It is harsh to touch. It looks like fescue in appearance. The leaves which are harsh to touch are <5mm wide, flat, strongly ribbed on the upper surface, rough bristly edges. They have 3 mm long smooth ligules. The leaves upper surface is a bright green, the underside is a dull grey-green. 
During November and December, it forms large, drooping, purplish, loose flower heads up to 40 cm long. The seed heads are a distinctive purplish colour and are hard, hairy, and have a pointed callus with very sharp, penetrating base.
An unusual feature of Nassella neesiana is that, in addition to normal flower seeds, it produces hidden seeds which are formed in the nodes and bases of the flowering stems. These ‘stem seeds’ are self-fertilised and account for about one-quarter of total seed production. They enable the plant to reproduce despite grazing, slashing and fire. This grass builds up a large and persistent seed bank in the soil. Nassella neesiana can produce more than 20,000 seeds per square metre. The seeds are spread by being transported by livestock, in hay, on clothing, by machinery. Floodwater will move seeds downstream.
Nassella neesiana is unpalatable to stock and will form dense clumps even in grazed areas, hence reduces pasture productivity.
The long, sharp seeds damage pelts, blind livestock (lambs are particularly vulnerable). The seeds can move through animals skin into muscles, causing abscesses.


The floret

A seed closeup, note the feathery sharp tip, collar at the base of the seedhead and the twisted tail.

The photo below shows the tail of the seeds that attached to the lamb head

The seeds can attach to any animal including mud in hooves.

Watch this video to learn how to identify Chilean Needle Grass and what you can do to. 

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