Olearia chathamica Kirk, Olearia chathamica Kirk var. chathamica, Olearia chathamica var. dendyi Cockayne, Olearia oporina Hook.f.
Vascular – Native
Trees & Shrubs - Dicotyledons
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 = 108
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.
2018 | Threatened – Nationally Vulnerable
Previous conservation statuses
2017 | Threatened – Nationally Vulnerable | Qualifiers: IE, PD
2012 | At Risk – Declining | Qualifiers: IE, PD
2009 | At Risk – Declining | Qualifiers: IE, PD
2004 | Range Restricted
Flat-topped small tree with narrow leathery saw-edged dark green leaves that are white underneath and large whiteish daisy-like heads inhabiting the Chatham Islands. Leaves 2.5-8cm long by 1.5-4cm wide, widest at middle, many even small thick teeth along edge. Flowers 3-4.5cm wide, petals white, centre purple.
Endemic. Rekohu (Chatham Island) where it is known from the southern tablelands, Rangihaute (Pitt), Mang’ere, Tapuaenuku and Hokorereoro (South-east) Islands.
Colonising rocky spurs, steep coastal cliffs and scarps, valley heads or open disturbed forest overlying forest peat soils. Mostly colonising sites that are steep or rocky so inaccessible to stock. Olearia chathamica avoids waterlogged ground and peat bogs, though occasionally it has been found on the margins of sphagnum bogs, or fringing lake shores where it grows on steep sided scarps.
Small, much-branched tree 6–8 m tall with broad spreading canopy (trees usually broader than tall), trunk erect often sinuously curved, up to 0.3 m d.b.h., near base, clad in stringy bark, bark grey, yellow-grey or dark grey, flaking in long strips that dettach from base. Branches numerous, virgate, erect (often forming a tighting interlocking canopy), (5–)6(–8) mm diameter, terete, brittle, young branches densely invested in white, appressed to patent floccose tomentum; tomentum shedding as branch matures. Leaves alternate, subsessile, coriaceous, arranged in shortly spaced spirals at branch apices; petiole 1.8-3.2 × 6-8 mm, base buttessed (raised as a small collar), otherwise plano-convex, densely covered in white, appressed floccose hairs; lamina 70-100(-120) × 16-20(-30) mm, lanceolate, elliptic, oblong-lanceolate or oblong-ovate, acute, adaxially light to dark green, glossy, initially sparingly furnished with caducous white, appressed floccose hairs along midrib and lamina margins, maturing glabrous, margins serrate in distal two-thirds, sometimes for entire length, teeth blunt, in 18–22 or more unequal pairs; apex acute; base attentuate. Inflorescences terminal, subterminal, axillary. Peduncules 50-80(-90) mm long, erect or curved, stout (6–8 mm diameter), terete, white tomentose, bracteate, bracts 3-5 or more, lanceolate, linear-lanceolate to deltoid, entire or toothed, teeth, 3-4 or more, surfaces clad in caducous white, appressed tomentum, otherwise glossy green to dark green. Capitula (50–)60 mm diameter. Involucrellum obconic, involucral bracts imbricate, numerous, up to 10 mm long, narrowly lanceolate, acute, abaxially clad in spreading, cobwebby white hairs, apex acute, glabrous green; ray-florets (60-)80-100, (8-)12-16 × 4-5(-6) mm, glabrous, usually slight decurved toward apex, linear, linear-oblong, oblanceolate, apices acute, subacute to obtuse usually minutely retuse and mucronate, mucro minute; surfaces usually white, sometimes white-tinged lavender, lavender and then fading to white after anthesis, very rarely purple (var. dendyi race); disc-florets (20-)22-26, corolla, aubergine, purple to dark violet (almost black) anthers dark orange yellow, stigma magenta. Cypsela (3.5–)4.0–5.8 mm long, narrowly oblong-obtriangular, narrowly oblong-obovate, compressed, often biconvex, base cuneate, ribbed 9–11×, ribs obscuring surface, otherwise smooth, sparsely to moderately furnished with short, white antrorse hairs, densely glandular, ribs pale orange-yellow to tan. Pappus 3.5–5.5 mm long, pale orange-yellow to pale brown.
Very close to teteaweka (Macrolearia angustifolia) and Macrolearia oporina both coastal species endemic to the Rakiura (Stewart Island), Foveaux Straight and Fiordland coastline. Differing from those species by the shorter, broader leaves, and from M. oporina by the mainly elliptic or oblanceolate-elliptic leaves, whose margins have shallow sinuses; and by the aubergine-coloured rather than usually yellow disc-florets (however sometimes these may be purple) - see comments by Saldivia et al. (2022). On the Chatham Islands keketerehe could only be confused with hangatere (Macrolearia semidentata). Hangatere is a spindly, sparingly branched shrub growing up to 2 m tall, which has shorter leaves which are sparingly, or coarsely toothed in the upper half to third shorter, and dark mauve (rarely pink) ray florets. Occasional hybrids between hangatere and keketerehe have been collected, notably from Rangaika where the ranges of both species overlap due to past land disturbance along the fringes of a restiad bog.
October - March
November - April
Keketerehe is threatened by fire, browsing animals (sheep, cattle, pigs and possums) and land clearance for farming. Forest degradation on the southern tablelands, as a consequence of unrestricted stock access, and feral animals also threatens this species. Recruitment failure in many populations has resulted in moribund stands verging on the point of collapse. The species is now secure only on cliffs east of Rangaika on Rēkohu (Chatham Island), the southern and south-western coastal portion of Rangihaute (Pitt), and on Mang’ere and Hokorereoro (South-east) islands.
chathamica: From the Chatham Islands
Where To Buy
Not commercially available.
Fact Sheet prepared for NZPCN by P.J. de Lange 28 April 2022. Description by P.J. de Lange (28 April 2022)
References and further reading
Saldivia, P.; Wagstaff, S.J.; Breitwieser, I.; Orlovich, D.A.; Lord, J.M. 2022: A Generic Taxonomic Synopsis of the Pleurophyllum Clade (Asteraceae: Astereae: Celmisiinae) with the Recognition of the New Zealand Endemic New Genus Macrolearia. Systematic Botany 47: 607–634
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Macrolearia chathamica Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/macrolearia-chathamica/ (Date website was queried)