Lophomyrtus obcordata
Common names
rōhutu
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Bushy shrub with a corded smooth trunk under flakes of bark bearing small thick heart-shaped leaves. Leaves 5–10 mm long, with a distinct notch at tip. Flowers white, single, 6 mm wide, with many filaments from white glossy centre, on a stalk to 20 mm long. Fruit red to black.
Flower colours
Cream, White
Detailed description
Shrub up to c. 6 m tall. Trunk slender, up to 0.2 m diameter. Bark greyish pink, chartaceous, flaking in large, irregular shards, underbark pale cream. Branches numerous, erect, compactly branched to spreading. Branchlets intially 4-angled maturing subterete, rather brittle, minutely pubescent. Leaves opposite (sometimes in fascicles), coriaceous, puberulent when young (hairs patent), becoming glabrous with age, glandular punctate, oil glands colourless, leaf lamina and petioles shortly decurrent with branchlet; petiole 0.7–1.0 mm long, brittle; leaf lamina 5–12 × 5–10 mm, obcordate, cuneately narrowed to base, adaxially dark green to grey-green (sometimes tinged red), paler beneath (sometimes tinged pink). Flowers 4-merous, 6–8 mm diameter, borne in axillary, solitary monads on slender, 10–14–(20) mm long, pubescent pedicels. Hypanthium subturbinate, not extending beyond ovary summit, glandular punctate, oild glands colourless (rarely pink tinged), calyx lobes 4, 1.0–1.8 mm long, persistent, spreading, pubescent, oblong, acute. Petals 6–8 × 5–8 mm, suborbicular, white, margins entire to slightly irregular, oil glands colourless. Stamens 60–80–(100 or more), free, in 4 weakly defined whorls, filaments 6–8 mm long, anthers cream, dorsifixed, latrorse. Ovary inferior, 2–3-locular, ovules numerous, in a single row on each linear placenta. Style 6–8 mm long, slender, white, stigma capitate, scarcely dilated. Fruit a broadly ovate, bright to dark red (rarely black or violet) 6–7 mm long berry. Seeds numerous, reniform, 2.0–4.3 mm diameter, testa pale brown, glossy ± smooth, very hard.
Similar taxa
Lophomyrtus bullata differs from L. obcordata by having much larger, distinctly bullate (“bubbly”) suborbicular rather than non-bullate obcordate leaves. Neomyrtus pedunculata could be confused with Lophomyrtus obcordata but it has obovate-oblong to obovate rather than obcordate leaves, and 5-merous flowers. Often in places where the ranges of Lophomyrtus bullata and L. obcordata overlap the hybrid L. ×ralphii can be found (and sometimes only this hybrid is present, the parents presumably having died out for that area). Like Lophomyrtus bullata the hybrid has suborbicular leaves, only smaller (up to 16 × 12 mm), and less distinctly or weakly bullate. It is fully fertile and often forms introgressive hybrid swarms. Lophomyrtus ×ralphii is popular in cultivation.
Distribution
Endemic. New Zealand: North Island (more common in the east, though locally prominent in some parts of western Northland and Auckland), South Island (more common in the east). Patchy distribution and often absent over large parts of the country.
Habitat
Coastal to montane in forest—though mostly found in coastal and lowland forested habitats. Lophomyrtus obcordata is often rather local over large parts of its North Island range though it seems to be reasonably common on the Pouto, Kaipara and Awhitu Peninsulas where it grows on stable sand dunes in a forest dominated by Kunzea amathicola (known as rawiritoa to northern Māori (de Lange 2014)). Lophomyrtus obcordata is also occasionally dominant in alluvial forest remnants of the eastern South Island. In these places it is often parasitised by the dwarf mistletoe Korthalsella lindsayi.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | At Risk – Declining | Qualifiers: DPT
Threats
Seriously threatened by the arrival of myrtle rust (Austropuccinia psidii) in New Zealand (de Lange et al. 2018). Learn more at myrtlerust.org.nz.
Detailed taxonomy
Family
Synonyms
Eugenia obcordata Raoul, Myrtus obcordata (Raoul) Hook.f.
Endemic taxon
Yes
Endemic genus
Yes
Endemic family
No
Ecology
Flowering
November–March
Fruiting
January–May
Propagation technique
Easily grown from fresh seed. Can also be grown from semi-hardwood and hardwood cuttings. Lophomyrtus obcordata is an attractive and remarkably hardy shrub that does well in a wide range of situations. of the two species in the genus, L. obcordata is more commonly grown and sold by nuseries though even then it is still surpassed in nurseries by the diversity of freakish forms and variegated mutants derived from the hybrid L. ×ralphii (L. bullata × L. obcordata). Myrtle rust (Austropuccinia psidii) however now poses a serious threat to this species both in the wild and in cultivation.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Other information
Etymology
lophomyrtus: From the Greek lophos (crest) and myrtus (myrtle)
obcordata: Heart-shaped and notched at the tip
Manaaki Whenua Online Interactive Key
NVS code
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.
LOPOBC
Chromosome number
2n = 22
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Critical | Qualifiers: DP
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | At Risk – Regionally Naturally Uncommon | Qualifiers: De, DPS, PF, Sp
Referencing and citations
References and further reading
de Lange PJ. 2014. A revision of the New Zealand Kunzea ericoides (Myrtaceae) complex. Phytokeys 40: 185 p. https://doi.org/10.3897/phytokeys.40.7973.
de Lange PJ, Rolfe JR, Barkla JW, Courtney SP, Champion PD, Perrie LR, Beadel SM, Ford KA, Breitwieser I, Schönberger I, Hindmarsh-Walls R, Heenan PB, Ladley K. 2018. Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series 22. Department of Conservation, Wellington, NZ. 82 p. https://www.doc.govt.nz/globalassets/documents/science-and-technical/nztcs22entire.pdf.
Webb CJ, Simpson MJA. 2001. Seeds of New Zealand Gymnosperms and Dicotyledons. Manuka Press, Christchurch. 428 p.
Attribution
Fact sheet including description prepared for NZPCN by P.J. de Lange 9 February 2011. Seed description modified from Webb & Simpson (2001).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Lophomyrtus obcordata Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/lophomyrtus-obcordata/ (Date website was queried)