Kunzea triregensis
Common names
Three Kings kānuka
Biostatus
Native
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
White
Detailed description
Shrubs or trees up to 18 × 3 m. Trunk 1–4, 0.10–0.85 m d.b.h. Bark grey or grey-brown, ± elongate, tessellated, usually bearing a few transverse cracks, firmly attached, detaching basally with age, and peeling upwards along trunk in broad, tabular strips. Branches numerous; upright to somewhat spreading; branchlets numerous, slender; branchlets sericeous, indumentum copious; hairs long appressed, usually flexuose (220)–480–(520) μm long. Leaves sessile; lamina 6.0–13.5 × 1.1–2.3 mm, dark glossy green above, paler beneath with leaf margins and midrib appearing distinctly white because of dense hair growth; lamina lanceolate to narrowly lanceolate; usually strongly recurved for about half of total length; apex acute to narrowly acute, base attenuate; lamina margin completely obscured by dense covering of antrorse-appressed hairs aligned in a thick, up to 0.6 mm wide, almost plumose, white band meeting at leaf apex. Inflorescence an elongated 3–20-flowered botryum up to 200 mm long, basal portion sometimes bearing compact, lateral 3-flowered corymbiform botrya, or with the basal and terminal portions occasionally bearing lateral elongate botyra; distal portions often interrupted by sections of leafy perules between which are spaced further flowers; or interrupted by short floral shoots bearing elongated 3–6-flowered botrya up to 20 mm long; terminal portion often bearing undeveloped flowers and vegetative terminal growth. Inflorescence axis densely invested in antrorse-appressed, weakly flexuose, hairs. Pherophylls persistent, foliose, 6.0–12.8 × 0.9–2.2 mm, dark glossy green, elliptic, broadly lanceolate to lanceolate; apex acute, base attenuate; lamina margin obscured by dense covering of antrorse-appressed, silky hairs. Pedicels subsessile to pedicellate 0.4–3.7 mm long copiously invested in antrorse-appressed, weakly flexuose, silky hairs. Flower buds double-conic to ovoid, calyx lobes prior to bud burst held flat or suberect with lobes ± meeting. Flowers 6.3–12.3 mm diameter. Hypanthium 1.6–4.4 × 2.0–4.6 mm, dark green or red-green; hemispherical to broadly obconic, sometimes campanulate or rarely cupular, densely to sparsely covered in silky, appressed antrorse hairs. Calyx lobes 5, erect, 0.5–1.3 × 0.3–0.8 mm, deltoid to ovate-deltoid, green to red-green; margins pale green often flushed pink, glabrescent. Receptacle green at anthesis, darkening to crimson after fertilisation. Petals 5–6, 1.3–4.3 × 1.9–4.8 mm, white, orbicular to broadly ovate, apex rounded, margins ± finely and irregularly denticulate, oil glands colourless. Stamens 30–53 in 1–3 weakly defined whorls, filaments white. Anthers dorsifixed, 0.05–0.10 × 0.06–0.08 mm, testicular-ellipsoid, latrorse. Pollen white. Anther connective gland prominent, pink or golden-yellow when fresh, drying yellow to pale orange, spheroidal, finely to coarsely papillate. Ovary 4–5 locular, each with 20–38 ovules in two rows on each placental lobe. Style 1.9–3.1 mm long, white or pinkish-white; stigma broadly capitate, wider than style, ± flat, greenish-white or pale pink, flushing red after anthesis, surface granular-papillate. Fruits 1.9–5.2 × 2.0–4.9 mm, dark chestnut-brown, maturing grey, hemispherical, broadly obconic, campanulate to cupular. Seeds 0.50–1.10 × 0.50–0.80 mm, oblong, oblong-obovate; testa semi-glossy, orange-brown to dark brown; surface coarsely reticulate.
Similar taxa
Morphologically Kunzea triregensis is mostly likely to be confused with Kunzea amathicola and K. linearis (de Lange 2014). In particular the distinctive elongate botrya of K. triregensis is seen otherwise only in K. amathicola, a species from which K. triregensis differs by its homophyllous growth habit, and lanceolate to narrowly lanceolate leaves. The peculiar ability of the K. triregensis inflorescence to produce, albeit infrequently, additional lateral elongate or reduced corymbiform botrya from the base and terminus of the main botryum further distinguishes it from K. amathicola. Kunzea tiregensis differs from K. linearis by its more openly vegetated, less densely crowded branchlets, and by the leaves which in K. triregensis are consistently lanceolate to narrowly lanceolate rather than linear. Further, in K. triregensis the thick bands of marginal and abaxial midrib hairs meet at the leaf apex, whereas in K. linearis the marginal hairs meet just short of the adaxial face of the apex and the abaxial midrib hairs stop short of the apex. The inflorescence of K. triregensis is consistently elongated and the flowers are usually widely spaced (only in stressed conditions becoming crowded). In contrast, the inflorescence of K. linearis is usually a condensed, densely packed spiciform botryum. Other distinctions are offered by de Lange (2014) who also discusses this species peculiar past confusion with the Great Barrier Island (Aotea Island) endemic Kunzea sinclairii.
Distribution
Endemic. New Zealand: Manawatāwhi / Three Kings Islands (Manawatāwhi / Great Island, Moekawa / South West Island, Ōhau / West Island, Oromaki / North East Island)
Habitat
Coastal forest—on Manawatāwhi / Great Island forms the dominant tree canopy.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 – Naturally Uncommon | Qualifiers: IE
Threats
Kunzea triregensis as K. aff. ericoides (e) (AK 226797; Three Kings) was appropriately listed by de Lange et al. (2013) as ‘At Risk/Naturally Uncommon’ qualified ‘IE’ (Island Endemic) and ‘OL’ (One Location) because the species is confined to one island group. In its island habitat Kunzea triregensis forms the dominant vegetation of Manawatāwhi / Great Island. When myrtle rust (Austropuccinia psidii) was detected in New Zealand (May 2017) the conservation status was upgraded as a precautionary measure to ‘Threatened – Nationally Critical’ because, on best advice, it was believed that no indigenous Myrtaceae had resistance to the myrtle rust disease (de Lange et al. 2018). Currently there have been no reports of infected wild trees of Kunzea but inoculation trials of the New Zealand species has demonstrated they are susceptible, and further that over time, infected specimens will die. Only time will tell if wild populations of Kunzea will be threatened by this rust fungus.
Myrtle rust (Austropuccinia psidii) is an invasive fungus that threatens native myrtle species. Learn more myrtlerust.org.nz
Detailed taxonomy
Family
Myrtaceae
Synonyms
None - first described in 2014
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
July–May
Fruiting
October–May
Propagation technique
Very easy from fresh seed. Can be grown from semi-hardwood and hardwood cuttings. Although scarce in cultivation Kunzea triregensis has proved to be an excellent fast growing tree, ideal for street side verges. It is very tolerant of drought and a range of soils provided it has good drainage. It does not appear to be especially cold sensitive.
Other information
Etymology
kunzea: Named after Gustav Kunze (4 October 1793, Leipzig -30 April 1851), 19th century German botanist from Leipzig who was a German professor of zoology, an entomologist with an interest mainly in ferns and orchids
triregensis: Literally ‘of the Three Kings’ - this species is endemic to the Three Kings Islands
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.
KUNTRI
Chromosome number
2n = 22
Previous conservation statuses
2017 | Threatened – Nationally Critical | Qualifiers: DP, IE
2013 | At Risk – Naturally Uncommon
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, Champion PD, Courtney SP, Heenan PB, Barkla JW, Cameron EK, Norton DA, Hitchmough RA. 2013. Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington, NZ. 70 p. https://www.doc.govt.nz/globalassets/documents/science-and-technical/nztcs3entire.pdf.
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.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 25 August 2014. Description modified from de Lange (2014).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Kunzea triregensis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/kunzea-triregensis/ (Date website was queried)