Lachnagrostis tenuis
Common name
Wind grass
Synonyms
Deyeuxia billardierei var. tenuis Cheeseman, D. tenuis (Cheeseman) Zotov
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.
LACTEN
Current conservation status
The conservation 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). 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.
2012 | Threatened – Nationally Vulnerable | Qualifiers: RR
Previous conservation statuses
2009 | Data Deficient
2004 | Range Restricted
Distribution
Apparently a local endemic. Confined to the South Island from Christchurch south along the Otago Coast to Bluff and on Stewart Island. At sites without grazing can be very common, though in the absence of a panicle it is very inconspicuous
Habitat
Coastal scrub and open ground and at sea level in salt marshes and other estuarine habitats. In saltmarshes it appears to prefer vegetated slightly raised sandy ground. Often in association with Sellieria radicans. The detached panicles accumulate along the strand line of estuaries.
Features
Stiff, leafy tufts 180-360 mm tall, leaves narrow, more or less inrolled, panicles lax. Branching intravaginal. Leaf-sheath subcoriaceous, more or less obviously ribbed, glabrous, light brown. Ligule 1.0-3.2 mm, truncate, erose, minutely ciliate, undersides scabrid. Leaf-blade 20-120 x 0.3-0.9 mm, inrolled, undersides smooth, rarely scabrid near apex, upper surface ribbed and short-scabrid on ribs, margins smooth, apex obtuse. Culm 50-200 mm, usually included within uppermost leaf-sheath, internodes densely, finely scabrid below panicle. Panicle 30-120 x 20-120 mm, delicate, branches fine, scabrid, erect to spreading, bearing spikelets at tips. Spikelets 3-5 mm, light green to light brown. Glumes 1-3-nerved, elliptic-lanceolate, more or less acuminate, strongly keeled, keel finely scabrid in upper half to two-thirds. Lemma 3.0-4.2 mm, more or less equivalent in length to glumes, firmly membranous, glabrous, papillose-scabrid, elliptic-lanceolate, lateral nerves sharply excurrent to c. 1mm; central awn 3.5-.6.5 mm, geniculate, emanating from lower one third of lemma. Palea 2.5-3.0 mm, c. two-thirds length of lemma, lanceolate, apex bifid, keels scabrid, margins submembranous, scabrid near apex. Callus hairs more or less dense, very short, 0.3-0.8 mm, about one quarter length of lemma. Rachilla prolongation 1.5-2.5 mm long, with very short hairs throughout except sometimes near tip, rarely completely glabrous. Lodicules 0.7-1.0 mm, lanceolate, acute. Anthers 0.5-0.9 mm. Seed 1.4-1.6 x 0.5-0.7 mm.
Similar taxa
Distinguished from the other New Zealand species of the genus by the intravaginal branching; glabrous lemma, and inrolled leaf-blades, that are 0.3-0.9 mm diameter, spikelets 3-5 mm long, and lemmas that are papillose-scabrid throughout (hand lens needed). The combination of narrow filiform leaves (rarely flat and to 2mm wide), geniculate awn, and glabrous lemma (though care must be taken as the hairy rachilla can give the adaxial part of the lemma a hairy appearance)distinguishes this species from any other coastal Lachnagrostis.
Flowering
Unknown
Fruiting
Unknown
Propagation technique
Unknown, but probably easy from fresh seed and rooted pieces.
Threats
Threats to this species include grazing, competition with creeping bent (Agrostis stolonifera) and Elytrigia spp. Some salt marsh habitat has been lost through reclamation.
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).
Where To Buy
Not commercially available
Attribution
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.