Chatham Island astelia, Chatham Island kakaha, Moriori flax
Astelia nervosa var. chathamica Skottsb.
Vascular – Native
Herbs - Monocots
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.
2n = 70
Current conservation status
The threat classification 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) – more information about this can be found on the NZTCS website 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. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | At Risk – Recovering | Qualifiers: CD, IE, RR
Previous conservation statuses
2012 | At Risk – Recovering | Qualifiers: CD, IE, RR
2009 | At Risk – Recovering | Qualifiers: IE, RR
2004 | Threatened – Nationally Endangered
Kakaha has long flax-like leaves clad in silvery hairs. Male and female flowers are found on separate plants. The male flower stalk is very thick and bears dark green, scented flowers, while the female plant has pale, greenish-white flowers. Flowering occurs from October to December, while the orange or red fruit may be seen from February to July.
Endemic to the Chatham Islands where it is known from Chatham Island and Pitt Island.
Kakaha occupies a range of moist sites. It can be found on forest floors, cliffs, rock bluffs, lakeshore scarps and stream margins, as well as in swamps. It was formerly widespread, but now tends to be restricted to sheltered, rocky, or protected spots in the bush or scrub where it is safe from grazing.
Wetland plant indicator status rating
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Robust tufted plant. Leaves 60–200 × 4–10 cm., keeled near the sheath, less so in main part of lamina; sheath-base white, with close scales on both surfaces; lamina adaxially silvered green with a metallic sheen, covered with a thin but long-persistent clear pellicle that lifts off in strips from old leaves; abaxial surface with a pale grey satiny indumentum of appressed scales with very little wool, the single main costa on each side of midrib little if at all stronger than midrib and not prominent. Inflorescence large and erect, most parts shaggy with narrow scales at least when young; lower spathes long; racemes numerous, all spathes except the smallest subtending sub-inflorescences of 2–3 or more racemes. Flowers pedicellate and usually well-spaced; male flower pale, tepals to 8 × 2.5–3 mm., strongly reflexed soon after flower opens; perianth-tube very short, drooping around pedicel and so exposing the base of the pistillode; outer tepals scaly externally; female flower colour not known, tepals more scaly, longer and proportionately narrower than in related species. Ovary 3-locular; style rather well-developed. Fruit about 10 × 10 mm., subglobose, orange; matured perianth fleshy, the tube retroflexed and much shorter than the persistent, membranous, more or less curled-under tepals.
October - December
February - July
Fleshy berries are dispersed by frugivory (Thorsen et al., 2009).
Browsing and physical destruction by stock and feral animals have impacted severely on this species.
chathamica: From the Chatham Islands
Where To Buy
Commonly available as Astelia cv. Silver Spear.
Type locality: Chatham Island. Type: K, Travers. This appears to be the only species on Chatham Islands; earlier records of different species probably all refer to this same plant.
In most inflorescences seen the bracteoles near the tips of the racemes are long and conspicuous, projecting far beyond the flowers. In some other species this development appears sporadically rather than as a consistent specific character.
Fact Sheet prepared for NZPCN by P.J. de Lange 1 August 2003.
Description adapted by M. Ward from Moore & Edgar (1970).
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Volume II. Indigenous Tracheophyta: Monocotyledones except Gramineae. Wellington, N. Z. pg. 34.
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.
Walls, G.; Baird, A.; de Lange, P.J.; Sawyer, J.W.D. 2002: Threatened plants of the Chatham Islands. Wellington, Department of Conservation.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Astelia chathamica Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/astelia-chathamica/ (Date website was queried)