The New Zealand Plant Conservation Network

Species

Austroderia turbaria

Common Name(s)

Chatham Island toetoe

Current Conservation Status

2012 - Threatened - Nationally Endangered

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 - Threatened - Nationally Endangered
2004 - Threatened - Nationally Critical

Qualifiers

2012 - CD, IE, RF, RR
2009 - CD, RF, IE, RR

Authority

Austroderia turbaria (Connor) N.P.Barker et H.P.Linder

Family

Poaceae

Flora Category

Vascular - Native

NVS Species Code

AUSTUR

Structural Class

Grasses

Synonyms

Cortaderia turbaria Connor

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.

Features

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 x 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.

Flowering

October - January

Fruiting

December - July

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.

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.

Chromosome No.

2n = 90

Endemic Taxon

Yes

Endemic Genus

Yes

Endemic Family

No

Life Cycle and Dispersal

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

This page last updated on 2 Jul 2014