The New Zealand Plant Conservation Network

Species

Coprosma chathamica

Etymology

Coprosma: from the Greek kopros 'dung' and osme 'smell', referring to the foul smell of the species, literally 'dung smell'
chathamica: From the Chatham Islands

Common Name(s)

Chatham Island karamu, karamu

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - At Risk - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - IE, RR
2009 - IE

Authority

Coprosma chathamica Cockayne

Family

Rubiaceae

Brief Description

Canopy tree with pairs of oval leaves inhabiting scattered sites on the Chatham Islands. Twigs and leaf bases bearing small hairs. Leaves with pale veins which have a small pit at some of their junctions, those of juvenile plants to 12cm long, those of adults only 3-4cm long. Ripe fruit yellow.

Flora Category

Vascular - Native

NVS Species Code

COPCHA

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

None (first described in 1902)

Distribution

Endemic. Chatham Islands group: Rekohu (Chatham Island), Rangiauria (Pitt Island) and Rangatira (South-east Island)

Habitat

Coastal and inland forest. Mostly on peat and usually in sites that are at least temporarily waterlogged but also on limestone, schist and basalt outcrops in free draining situations. An important canopy tree which co-associates with matipo (Myrsine chathamica) on free draining soils, and swamp akeake (Olearia telmatica) in the waterlogged soils in the lowlands to form one of the main forest types. It is also prominent with tarahinau (Dracophyllum arboreum) in the southern tablelands forests, and less frequently with akeake (Olearia traversiorum) in dune forest and overlying basalt or schist.

Features

Tree up to 15 m tall; trunk up to c.600 mm diameter; branches and branchlets rather stout, densely pubescent when young. Leaves on short 8-10 mm long fleshy-coriaceous petioles. Stipules triangular, pubescent, densely ciliate; apical denticle prominent black, surrounded on either side by 2-4 smaller denticles. Lamina of juvenile leaves subcoriaceous, 45-75 × 20-45 mm, dark green to green, broadly ovate to ovate-oblong, obtuse, mucronulate, base cuneately narrowed, margins often hairy; adult lamina 20-35 × 15-30 mm, dark green and rather glossy above, paler below, ovate to ovate-oblong, elliptic to oblong-elliptic, obtuse, mucronulate, base cuneately narrowed, margins slightly recurved, entire to distinctly undulose. Reticulated veins not or scarce evident above, evident below. Male flowers solitary or in clusters of up to 6 on shortly branched axillary peduncles; calyx 0 or vestigial; corolla funnelform, lobes 5, acuminate, > tube. Female flowers 1-6 together; calyx-teeth short, ciliolate; corolla tubular, lobes ovate, acute, > tube. Drupe yellow-red to orange, obovoid, slightly compressed to subdidymous, c.9-12 × 9-14 mm.

Similar Taxa

A very distinctive species which on the Chatham Islands is not likely to be confused with any of the other Coprosma species present. The tree growth habit marks it well in the field, while the very large juvenile leaves with their usually distinctly hairy margins and smaller glossy, dark green adult leaves which usually have distinctly undulose margins readily distinguish it. Allan (1961) followed W.R.B. Oliver and placed it as close to C. petiolata (Kermadec islands) and C. repens in Sectionion Petiolatae. Morphologically it has little to do with these two species, sharing more features in common (especially the growth habit, adult leag shape, fruits and pyrene morphology) with the arborescent Norfolk Island endemic C. pilosa. However, molecular data clearly shows that C. chathamica is closely allied to C. repens.

Flowering

August - December

Flower Colours

Green

Fruiting

November - May

Propagation Technique

Easily grown from fresh seed and semi-hardwood cuttings. An attractive species that given time will grow in to a large tree so it needs plenty of space. Does best planted in a permanently moist soil (it can tolerate periodic water logging).

Threats

An Island endemic that is not really threatened. One of the major forest trees on the Chatham Islands.

Chromosome No.

2n = 132

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Fleshy drupes are dispersed by frugivory (Thorsen et al., 2009).

This page last updated on 31 Mar 2016