Mountain wind grass
Agrostis lyallii Hook.f., Deyeuxia forsteri var. lyallii (Hook.f.) Hack. comb. illeg., var. epithet legit., D. forsteri var. semiglabra Hack. comb. illeg., var. epithet legit., Lachnagrostis filiformis var. semiglabra (Hack.) Zotov
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 = 98
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
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Endemic. Common in mountain regions from the Central North Island and throughout the South Island. Also recorded once from Northland, and around the western Waikato.
Usually montane in open tussock grassland, on cliff faces and rock outcrops and on rock outcrops. Sometimes along the margins of lakes and becoming more common in lowland areas heading south. Coastal on the Chatham Islands.
Wetland plant indicator status rating
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Usually large, rather laxly tufted, stoloniferous, perennial grass forming patches 50-150 mm with wide, flat, or narrow and folded, light or dull green leaves, and lax, often rather large panicles in proportion to plant. Sometimes short, densely tufted plants with narrow involute leaves. Branching extravaginal. Leaf-sheath submembranous, distinctly ribbed, smooth or minutely scabrid above, green to creamy brown, sometimes purplish. Ligule 0.6-4.0 mm, ovate-oblong, more or less truncate, denticulate to lacerate, undersides minutely scabrid. Leaf-blade 20.0-150.0 x 0.3-6.0 mm, flat or folded, upper surface smooth to finely scabrid on ribs throughout or near apex, undersides finely scabrid on ribs; margins minutely scabrid, apex subacute. Culm 30-450 mm, erect or geniculate at base, longer culms projecting beyond uppermost sheaths, internodes usually finely scabrid below panicle. Panicle 40-250 x 10-160 mm, very lax or sometimes contracted after flowering, with widely spreading, finally horizontal branches; branches rather few, very finely, more or less sparsely scabrid, with 1-2-several spikelets at branchlet tips. Spikelets 2.3-5.0 mm, pale green to light straw-coloured, greenish brown or purplish. Glumes subequal, ovate-elliptic or narrowly elliptic-lanceolate, acute, mid-nerve and hyaline margins scabrid near apex or in upper half. Lemma 1.5-2.8 mm, one-half to three-quarters length of glumes 5-nerved, with numerous to sparse, scattered, short fine hairs, sometimes glabrate, or the upper third glabrous, elliptic-oblong, truncate, lateral nerves slightly to obviously excurrent; awn 1.7-6.0 mm long, geniculate, more or less mid-dorsal. Palea about one-half length or equivalent in length to lemma, keels very faint, 0.1-0.2 mm apart, apex truncate, or obtuse, or shallowly notched. Callus hairs moderately dense, to 1 mm long, to one third length of lemma. Rachilla prolongations absent or up to 1 mm long, tipped by a few equally long, or longer hairs. Lodicules 0.7-0.9 mm, linear, acute. Anthers 0.3-1.5 mm. Seed 1.2-2.0 x 0.4-0.8 mm.
Manaaki Whenua Online Interactive Key
Distinguished from all other New Zealand species of Lachnagrostis by the extravaginal branching and geniculate awns. Lachnagrostis lyallii is rather variable and two forms have been provisionally recognised. A stout, lax, large plant with flat leaves and spikelets 4-5 mm long, glabrate to glabrous 2.5 mm long lemmas, palea about half the length of the lemma, and with anthers 0.8-1.2 mm long. The second form is much smaller, and has inrolled leaves, smaller spikelets 2.5-3.5 mm long, smaller, densely hairy lemmas, 1.8-2.2 mm long, with the palea three-quarters to about the same length of the lemmas, and rather short anthers (0.3-0.8 mm long). These forms appear to intergrade.
October - January
November - May
Easy from fresh seed. Prefers full sun, and minimal competition.
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).
lyallii: Named after David Lyall (1817-1895), 19th century Scottish naturalist and surgeon with the Royal Navy, who explored Antarctica, New Zealand, the Arctic and North America and was a lifelong friend of Sir Joseph Hooker.
There is some morphological evidence to suggest that Lachnagrostis lyallii, as currently circumscribed may warrant taxonomic revision. At least two entities are suggested based on a preliminary investigation.
Fact Sheet prepared for NZPCN by P.J. de Lange 14 April June 2005. Description modified from Edgar & 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 lyallii Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/lachnagrostis-lyallii/ (Date website was queried)