Agrostis imbecilla


Agrostis: Greek name for a kind of grass
imbecilla: weak

Common Name(s)

feeble bent

Current Conservation Status

2012 - Data Deficient

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - At Risk - Naturally Uncommon
2004 - Sparse


2012 - Sp


Agrostis imbecilla Zotov



Flora Category

Vascular - Native

NVS Species 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.

Structural Class



Agrostis tenella Petrie non Hoffm.


Endemic. North Island, one record from Moawhango. South Island, infrequent in Canterbury and Otago


A montane, subalpine to alpine species of damp sites within tussock grassland.


Delicate, slender, tufted perennial plants (100-)150-350 mm tall, with long, rather fine, spike-like panicles on slender culms > overtopping leaves. Leaf-sheath narrow, membranous, light cream-brown to reddish, glabrous, distinctly ribbed. Ligule 0.8-1.6 mm, obtuse, lower surface glabrous. Leaf-blade 20-130 x 0.2-0.4 mm, involute, filiform, flaccid, undersides finely striate and, in young leaves scabrid, upper surface scabrid on ribs; margins scabrid, apex tapered, blunt. Culm „b filiform, erect or geniculate at base, internodes glabrous. Panicle (25-)50-90 x 2-3 mm, contracted, narrow-linear, pale purple. Spikelets 1.5-2.4 mm, pale greenish purple or pale yellow. Glumes equal, lanceolate, scabrid on keel and on margins near acute tip. Lemma 1.5-1.9 mm, glabrous, 5-nerved, ovate-oblong, apex denticulate, usually without awns, if present these up to 1 mm, scarcely projecting beyond glumes. Palea 0.1-0.2 mm, ovate. Callus with few minute hairs. Anthers 0.6-1 mm.

Similar Taxa

A distinctive species characterised by its very fine, rather slender panicles, and rather lax to flaccid leaves.





Propagation Technique

Easy from fresh seed and rooted pieces but will not flower without cold treatment. In humid climates it is difficult to maintain


Not directly threatened, but listed because it is a naturally uncommon species of sporadic occurrence.

Chromosome No.

2n = 42

Endemic Taxon


Endemic Genus


Endemic Family


Life Cycle and Dispersal

Florets are dispersed by wind and water (Thorsen et al., 2009).


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.

Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 2009 Vol. 11 No. 4 pp. 285-309

This page last updated on 10 May 2014