Austroderia turbaria
Common names
Chatham Island toetoe
Biostatus
Native
Category
Vascular
Structural class
Grasses
Detailed description
Tall, hermaphrodite, tussock of wetlands. Leaf-sheath inter-nerves and margins conspicuously hairy. Ligule 2 mm. Collar underside glabrous, top side sparsely hairy. Leaf-blade up to 1.5 × 0.15 m, glaucous, tapering to long, thin point; under surface with long inter-rib hairs, upper surface with conspicuous, dense, weft of hairs at base otherwise glabrescent; lamina margins scabrid. Culm to 2 m, internodes glabrous. Inflorescences 400–800 mm, dense, plumose, drooping, branches and pedicels covered in copious long hairs, these longer than spikelet. Spikelets with 2 florets. Glumes equal, 25 mm or less, 1-nerved, thin; upper with 10 mm or less hairs, lower less hairy or glabrous. Lemma 9 mm. Palea 7 mm, long-hairy, apex hair-tipped, keels ciliate. Callus hairs 3 mm. Rachilla 1 mm, glabrous. Anthers 1.7–2.6 mm. Gynoecium with ovary to 0.8 mm, stigma-styles 2.5 mm. Seeds ovate, rugose, 3 mm.
Similar taxa
Austroderia turbaria is the only species of the genus native to the Chatham islands. It is allied to A. splendens Connor, which is endemic to the northern North Island. From that species it can be distinguished by its long-hairy leaf-sheaths, and hermaphrodite flowers. Austroderia fulvida and A. richardii have also been planted on the Chatham Islands, again A. turbaria is easily distinguished from these by its hairy leaf-sheaths and hermaphrodite flowers.
Distribution
Endemic to the Chatham Islands. Found on both Chatham and Pitt Islands.
Habitat
A species usually found on the margins of slowly flowing streams draining peat bogs, or on lake margins. It has also been found in light wells created by tree falls within swamp forest.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 | Threatened – Nationally Critical | Qualifiers: IE, RR, RF
Threats
This plant is one of the most threatened in the Chathams archipelago. As of 2005 there are ten wild populations and 344 mature plants known. These occur in often small and widely fragmented locations and so remain highly vulnerable to catastrophic events. Browsing and trampling by cattle is a major problem, and the species is also greedily devoured wherever sheep and pigs can reach it. There is some indication that fungal diseases such as Fusarium wilt may have been responsible for the recent near loss of this species from the northern part of Chatham Island. Fire, floods and competition from other vegetation are also threats. The species is also at some risk through hybridism with species of New Zealand toetoe that have been introduced to the Chatham Islands.
Detailed taxonomy
Family
Poaceae
Synonyms
Cortaderia turbaria Connor
Endemic taxon
Yes
Endemic genus
Yes
Endemic family
No
Ecology
Flowering
October–January
Fruiting
December–July
Life cycle and dispersal
Florets are wind dispersed (Thorsen et al., 2009).
Propagation technique
Austroderia turbaria is easily cultivated and does best in a sunny, sheltered site on permanently damp, peaty or acid soil. It is inclined to be rather short-lived (2–5 years) and will not tolerate drought. It is easily grown from fresh seed which germinates readily. Seed appears to have little viability if stored for longer than a year.
Other information
Where To Buy
Occasionally sold by some specialist native plant nurseries.
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.
AUSTUR
Chromosome number
2n = 90
Previous conservation statuses
2017 | Threatened – Nationally Endangered | Qualifiers: CD, IE, RF, RR
2012 | Threatened – Nationally Endangered | Qualifiers: CD, IE, RF, RR
2009 | Threatened – Nationally Endangered | Qualifiers: CD, RF, IE, RR
2004 | Threatened – Nationally Critical
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 1 October 2006. Description adapted from Edgar & 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.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Austroderia turbaria Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/austroderia-turbaria/ (Date website was queried)