Agrostis oresbia
Common names
mountain bent
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Grasses
Detailed description
Tufted or stoloniferous plants 50–250 mm, culms overtopping leaves. Leaf-sheath hyaline, light green to light brown, prominently ribbed, smooth, rarely with prickle teeth. Ligule 1–4.5 mm, truncate to obtuse, denticulate or entire, glabrous. Leaf-blade 20–70 × 1.5–2 mm, flat or folded, undersides smooth, upper prominently ribbed, margins usually smooth, sometimes sparsely to densely, scabrid, apex tapered, blunt, scabrid. Culm erect, internodes glabrous. Panicle (15–)20–60 mm, open, lax, oblong to pyramidal, with spreading or flexuous branches; rachis smooth, branches and pedicels smooth or scabrid. Spikelets 2–2.5(–3) mm, purplish. Glumes unequal, acute to acuminate, keel scabrid near apex, margins smooth, sometimes scabrid near apex; lower, 2–2.5(–3) mm, ovate-lanceolate, upper 1.7–2.5(–3) mm, elliptic-lanceolate. Lemma 1.5–2 mm, glabrous, faintly 5-nerved, ovate, obtuse; awn (1.5–)2–3 mm, geniculate, slightly projecting beyond glumes. Callus with minute hairs. Anthers 0.4–0.9 mm.
Similar taxa
Agrostis oresbia could be confused with A. magellanica Lam. but it is a smaller plant in all respects. It is perhaps closest to A. muelleriana Vickery from which it differs by its larger, more open, and laxer panicle, and by the glumes which are less scabrid and papillose. A. oresbia has a somewhat similar appearance to A. personata Edgar, from which it can be distinguished by its intravaginal innovations; awned lemmas; and by the abaxially smooth ligules. Palea 0.5 mm, ovate.
Distribution
Endemic. North Island (Raukumara, Ruahine and Tararua Ranges). South Island, North-West Nelson (Lake Aorere and Mt Domett only)
Habitat
A subalpine to alpine species frequenting damp seepages and water courses within tussock grassland and on rocky ground, shaded cliff faces or screes, occasionally on river flats.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Data Deficient
Threats
Not threatened but rather a naturally uncommon species of spradic occurrence which is why it has been listed
Detailed taxonomy
Family
Synonyms
None
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
Unknown
Fruiting
Unknown
Life cycle and dispersal
Florets are dispersed by wind and water (Thorsen et al., 2009).
Propagation technique
Unknown but should be easy from fresh seed and rooted pieces
Other information
Etymology
agrostis: Greek name for a kind of grass
Manaaki Whenua Online Interactive Key
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.
AGRORE
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | At Risk – Naturally Uncommon | Qualifiers: DP, Sp
2012 | At Risk – Naturally Uncommon | Qualifiers: DP, Sp
2009 | At Risk – Naturally Uncommon
2004 | Sparse
Referencing and citations
References and further reading
Edgar E, Connor HE. 2000. Flora of New Zealand. Vol. V. Grasses. Christchurch, Manaaki Whenua Press. 650 p.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange June 2005. Description modified from Edgar and Connor (2000).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.