Lachnagrostis striata
Common name
Purple wind grass
Synonyms
Agrostis striata Colenso, Deyeuxia forsteri var. humilior Hack. comb. illeg., var. epithet legit.
Family
Poaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Grasses
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.
LACSTR
Chromosome number
2n = 84
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.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Distribution
Endemic. In the North Island scattered from Auckland south, common on the Volcanic Plateau. South Island, locally common in the east but abundant in Fiordland.
Habitat
Lowland to montane. Usually found on lake and tarn margins (especially in turfs), on river banks and in damp seepages within tussock grassland.
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).
Features
Tufted, usually fine-leaved, low growing, tufted, bright green to red-green annual to short-lived perennial grass 50-400 mm tall. Branching extravaginal. Leaf-sheath membranous, sparsely ribbed, smooth, rarely minutely scabrid, green to light brown. Ligule 1.0-5.5 mm long, more or less oblong, sometimes slightly tapered, denticulate, undersides sparsely prickle-toothed. Leaf-blade 10-100 x 0.6-2.0 mm, usually folded, so appearing narrower, undersides smooth except near apex, upper surface scabrid on prominent ribs, margins scabrid; apex subobtuse. Culm 15-300 mm long, erect or ascending, longer culms often projecting beyond uppermost sheaths, internodes minutely, retrorsely scabrid. Panicle 20-200 x 15-120 mm, delicate, rather contracted at first, becoming lax; branches filiform, finely scabrid, tipped by 1-few spikelets. Spikelets 2.0-3.5 mm, green or purplish, sometimes purple-red. Glumes subequal, acute, scabrid on mid-nerve in upper half or almost throughout, hyaline margins with a very few prickle-teeth near apex; lower slightly longer, linear-lanceolate, upper elliptic-lanceolate. Lemma 1.2-2.3 mm, two-thirds to three quarters the length of glumes, usually densely covered by stiff, straight hairs, ovate-oblong, truncate, lateral nerves scarcely excurrent; awn 0.2-3.0 mm, mostly straight, rarely geniculate, very fine, often purple, emanating from upper third of lemma. Palea two-thirds to about the same length as the lemma, keels 0.1 mm apart, slightly excurrent, apex minutely bifid, sparsely prickle-toothed. Callus ringed with short hairs to 0.3 mm, about one quarter length of lemma. Rachilla prolongation 0.5 mm long, tipped by equally long, or slightly longer hairs. Lodicules 0.3 mm, linear, acute. Anthers 0.2-0.6 mm long. Seed 0.8-1.4 x 0.4-0.6 mm.
Similar taxa
One of a group of species with mostly straight or curved awns (though in this species they can be geniculate); extravaginal branching and with initially contracted panicles which later open and whose ultimate branches often bear two or three spikelets towards the apex; and whose lemma is 1.2-2.5 mm long. It is distinguished from L. uda Edgar and L. glabra (Petrie) Edgar, which also have these features, by the densely hairy lemma and by the anthers which are usually 0.2-0.5 mm long. Lachnagrostis striata is a lowland to montane species, often of river, lake, pond or tarn margins, while L. glabra is strictly coastal and usually associated with salt marshes and mud flats and L. uda a species of alpine seepages and mires.
Flowering
September - April
Fruiting
October - June
Propagation technique
Easy from fresh seed. Usually an annual or short-lived grass which readily self-sows and can become invasive.
Etymology
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).
striata: Striated
Where To Buy
Not commercially available.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (27 June 2005). 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 striata Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/lachnagrostis-striata/ (Date website was queried)