Nassella trichotoma
NPPA pest plant
Environmental Weed (2024)
Common names
nassella tussock
Biostatus
Exotic
Category
Vascular
Structural class
Grasses
Detailed description
Caespitose perennial with shoots swollen and white at base, and open purplish panicle, branching intravaginal. Sheath to 5 cm, scabrid near ligule and on upper margins, becoming glabrous below. Ligule to 1.5 mm, decurrent, symmetrical or asymmetrical, rounded or apiculate, short-hairy or scabrid. Leaf-blade to 35 cm × 0.5 mm diam., inrolled, appearing terete, very stiff, acicular, abaxially antrorsely scabrid, adaxially clothed in short dense hairs; margins smooth. Culm to 70 cm, glabrous except for hairs above and below nodes. Panicle to 25 cm, open, much-branched, drooping, at maturity readily detaching with culm and blowing freely; rachis, branches and pedicels scabrid. Glumes nearly equal, 5–8 mm, deeply purple-suffused, 3-nerved, produced into awn approx. 2 mm, nerves and margins stiff-hairy. Lemma to 2.5 mm, 5-nerved, gibbous, tubercular-scabrid except on margin, lobes short, apiculate; coma present; awn tardily caducous to 35 mm, weakly 1-geniculate, short stiff-hairy, column loosely twisted, to 15 mm, arista to 20 mm. Palea approx. 1 mm, completely enclosed by lemma, glabrous, hyaline, weakly bifid at apex. Callus to 0.3mm, blunt, hairs to 1.5 mm. Lodicules 2, to 1 mm in chasmogamous flowers, to 0. 6mm in cleistogamous flowers. Anthers penicillate, in chasmogamous flowers to 2 mm; in cleistogamous flowers 1 fertile anther to 0.7 mm, and 2 aborted anthers to 0.3mm. (Edgar & Connor, 2000)
Similar taxa
Finely serrated leaves give a rough feeling to the leaves. Fine feathery panicle with a purplish tinge.
Habitat
Terrestrial.
Conservation status
Not applicable
Detailed taxonomy
Family
Poaceae
Ecology
Flowering
October, November, December
Fruiting
October-December
Year naturalised
1931
Origin
S. America
Reason for introduction
Accidental
Life cycle
Perennial. Reproduces by seed only. Dispersed by wind, up to 16 km from the mother plant. The seeds, aided by the roughened seed coat and the tufts of hairs at the base, also cling to wool, bags, clothing etc. Seeds are also spread on machinery, in hay, mud and the droppings of animals.
Other information
National Pest Plant Accord species
This plant is listed in the 2020 National Pest Plant Accord. The National Pest Plant Accord (NPPA) is an agreement to prevent the sale and/or distribution of specified pest plants where either formal or casual horticultural trade is the most significant way of spreading the plant in New Zealand. For up to date information and an electronic copy of the 2020 Pest Plant Accord manual (including plant information and images) visit the MPI website.
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
NVS code
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.
NASTRI
Referencing and citations
References and further reading
Edgar E, Connor HE. 2000. Flora of New Zealand. Vol. V. Grasses. Manaaki Whenua Press, Christchurch, NZ. 650 p.