New Zealand wind grass
Avena filiformis G.Forst., Agrostis filiformis (G.Forst.) Spreng., Calamagrostis filiformis (G.Forst.) Cockayne, Deyeuxia filiformis (G.Forst.) Petrie, Agrostis avenacea J.F.Gmel., Agrostis forsteri Roem. et Schult., Deyeuxia forsteri (Roem. et Schult.) Kunth, Agrostis solandri F.Muell.
Vascular – Native
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.
2n = 56
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | Not Threatened | Qualifiers: SO
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Indigenous. Common throughout New Zealand. Found in Australia and on many of the Pacific Islands
Coastal to subalpine. Widespread in a variety of open situations and often found as an urban weed, especially in waste land around puddles and in muddy ground. Common around lakes, and fringing ponds, streams and on wetland margins. An opportunistic species that has probably increased its range following human settlement.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland).
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Rather variable, usually slender, upright, tufted, glaucous green, light green to yellow green, annual or short-lived perennial grass up to 700 mm tall; whole plant usually withering early and culms not breaking up below panicle. Branching intravaginal. Leaf-sheath firmly membranous, distinctly ribbed, glabrous below, very finely scabrid above. light green, later light brown. Ligule 1-5 mm, oblong, rounded or tapered, later lacerate, undersides with sparse prickle-teeth. Leaf-blade 25-200 x 1.5-3.0 mm, usually flat, sometimes involute and 0.5-1.0 mm diameter, glabrous, or ribs scabrid; margins very finely scabrid, apex finely acute. Culm 100-350 mm, erect to spreading, internodes usually densely, minutely scabrid, occasionally smooth. Panicle 90-300 x 5-250 mm, yellow green, faintly purple-green drying white, delicate, enclosed at base by the uppermost leaf-sheath, at first contracted, later very lax; branches filiform, numerous, unequal, very finely scabrid, primary branches naked for much of length, with spikelets in clusters of 2-many, towards tips of the much shorter capillary secondary branches. Spikelets 2.5-4.2 mm, pale silvery green to purplish. Glumes subequal, acute to acuminate, usually glabrous, membranous, very narrow linear-lanceolate, lower glume usually slightly longer and more acuminate; keel scabrid. Lemma 1.3-2.3 mm long, one half to two-thirds length of glumes, 5-nerved, moderately covered with very short hairs, oblong-ovate, glabrous near hyaline, truncate, erose apex, lateral nerves very short excurrent; awn 3-6 mm geniculate, more or less mid-dorsal or form c. upper one third. Pale three-quarters - four-fifths length of lemma, keels 0.1 mm apart, apex subobtuse. Callus ringed by minute hairs 0.3-0.4 mm, to one quarter of lemma. Rachilla prolongation absent or 0.3 mm long tipped with hairs to 0.8 mm long. Lodicules 0.5-0.9 mm,linear, acute. Anthers 0.2-0.3 mm. Seed 0.8-1.3 x 0.3-0.5 mm long.
Allied to L. littoralis (Hack) Edgar and one of a group of Lachnagrostis with geniculate awns and intravaginal branching. It is distinguished from all of these by its annual to short-lived perennial habit, delicate panicle and very narrow leaves (0.5-3.0 mm wide). From L. littoralis it differs by the obviously unequal lengths of the naked primary and secondary panicle branches, and by the lemma usually 1.3-2.0 mm (cf. 1.8-3.0 mm long in L. littoralis) and anthers 0.2-0.5 rather than 0.4-0.7 mm long. Lachnagrostis littoralis subsp. littoralis (and most populations of subsp. salaria Edgar) is strictly coastal and a much smaller, more delicate usually strictly annual grass than L. filiformis.
September - April
October - June
Easy from fresh seed, and infact, can be very weedy.
lachnagrostis: From “lachne” (wool) referring to the distinctive callus hairs of this genus and “agrostis” by which Trinius (1820) actually meant “a grass” (not an Agrostis). So the generic name means “a hairy (woolly) grass” not “a hairy (woolly) Agrostis” as is often incorrectly stated (see Gardner 2014).
filiformis: From the Latin filum ‘thread’ and forma ‘shape’, meaning thread-shaped
Where To Buy
Not commercially available. Quite weedy and can be found growing in urban and industrial areas.
Fact Sheet for NZPCN by P.J. de Lange 27 June 2006. Description modified from Edgar and Connor (2000)
References and further reading
Edgar, E.; Connor, H.E. 2000: Flora of New Zealand. Vol. V. Grasses. Christchurch, Manaaki Whenua Press. 650 pp.
Gardner, R.O. 2014: Notes on the wind grass Lachnagrostis filiformis (Poaceae). Auckland Botanical Society Journal 69: 168-170.
Trinius, C.B. 1820: Fundamenta Agrostographiae. J.G.Huebner, Vienna.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Lachnagrostis filiformis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/lachnagrostis-filiformis/ (Date website was queried)