Metrosideros diffusa Hook.f.
Vascular – Native
Lianes & Related Trailing Plants - 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 = 22
Current conservation status
The conservation 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). 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.
2018 | Threatened – Nationally Vulnerable
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Woody long-climbing vine. Mature plants only reproductive. Juvenile foliage hairy, with young growth often pinkish. Adult leaves more or less circular, dark glossy green above, pale green below, surfaces without any obvious glandular spotting. Flowers carmine borne in dense, terminal, fluffy, clusters.
Endemic. New Zealand: North Island (from Te Paki south to Taranaki in the west and Mahia Peninsula in the east)
Coastal to montane (mainly coastal to lowland). A vine of closed forest and forest margins (often along water ways and on ridge lines, especially on rock outcrops and cliff faces).
Vine up to 15 m (usually less). Bark dark brown to grey, ± tessellated, and flaking in tabular shards. Growth dimorphic, juvenile and climbing vines sparingly branched, mature (adult - reproductive state) heavily branched. Branchlets terete, finely pubescent. Leaves, close-set, coriaceous, petiolate; petioles 1-3 mm. long; lamina of juveniles 10-20 × 8-18 mm, suborbicular, orbicular to broadly ovate, apices obtuse to subacute; adaxially green to dark green, abaxially paler (young foliage (and branchlet growing points) usually pink-tinged), both surfaces finely to distinctly pubescent, hairs pinkish, oil glands conspicuous abaxially not punctate,; adult lamina 15-35 × 7-30 mm, elliptic-oblong, ovate-oblong to broad ovate, apices obtuse to subacute, adaxially dark green and glossy, adaxially paler, ± glossy, ± glabrous. Inflorescences in axillary and/or terminal few- to many-flowered cymose botyria crowded toward apex of branchlets (often obscuring the foliage); peduncles and pedicels finely pubescent, peduncles 20-60 mm long, pedicels 5-10 mm long. Hypanthium urceolate or globose, initially fleshy, finely pubescent, ± glabrescent; calyx lobes 1.8-2.3 mm long, oblong, subacute. Petals 5 × 4 mm, caducous, suborbicular, carmine, shortly clawed, margins ± unevenly crenulate to indistinctly toothed or undulose; stamens numerous 10-15 mm long carmine. Capsule 6-9 mm diameter, subglobose to globose, 3(-4)-valved, exserted, ± woody, dark brown to brown-black when mature.
Adult vines are easily recognised when flowering by the profusion of carmine flowers - quite unlike any other New Zealand rata vine. However, this species is most often found as juveniles, and these have a superficial resemblance to M. perforata. From that species M. carminea can be distinguished by the branch tips and young emergent leaves which are very hairy and tinged pink. Both species have prominent oil glands on their leaves but in M. carminea these are never pitted (punctate) like those of M. perforata.
August - November
January - April
Easily grown from rooted pieces. Also grown from semi-hardwood cuttings. Indeed adult plants are often propagated from cuttings and while these don’t climb they form an excellent small shrub suitable for rockeries and tub or pot culture. Metrosideros carminea is an excellent vine for growing up walls and rock faces, doing best if its roots are planted in a free draining, humus enriched, moist soil, and the plants allowed to climb up into the sun. Metrosideros carminea is frost sensitive and young vines will need to be carefully nurtured until they are well established.
Myrtle Rust (Austropuccinia psidii) is an invasive fungus which threatens native myrtle species - learn more myrtlerust.org.nz
Metrosideros carminea is most often found as juveniles, in part because the adult vines (at least in dense forest) are often overlooked as they occur high up in the canopy. In some areas adult vines are heavily browsed by possums.
metrosideros: Iron heart
carminea: Carmine or red-coloured
Where To Buy
Commonly available from most retail nurseries, though often sold as adult cutting grown plants only (these will not climb).
Fact sheet prepared for NZPCN by P.J. de Lange (5 January 2013). Description adapted from Allan (1961) supplemented with observations made from herbarium and fresh material.
References and further reading
Allan, H.H. 1961: Flora of New Zealand. Vol. I. Wellington, Government Printer.
Please cite as: de Lange, P.J. (Year at time of access): Metrosideros carminea Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/metrosideros-carminea/ (Date website was queried)