Species

Kunzea triregensis

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

Common Name(s)

Three Kings kanuka

Current Conservation Status

2018 - Threatened - Nationally Critical

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

2013 - At Risk - Naturally Uncommon

Authority

Kunzea triregensis de Lange

Family

Myrtaceae

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

None - first described in 2014

Distribution

Endemic. Three Kings Islands - North East, Manawatahi / Great Island, South West and West Islands

Habitat

Coastal forest - on Manawatawhi / Great Island forms the dominant tree canopy

Features

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 Aotea Island / Great Barrier Island endemic Kunzea sinclairii.

Flowering

July–May

Flower Colours

White

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.

Threats

Kunzea triregensis as K. aff. ericoides (e) (AK 226797; Three Kings) is 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 Manawatawhi / Great Islands.

Chromosome No.

2n = 22

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Attribution

Fact Sheet prepared for NZPCN by P.J. de Lange 25 August 2014. Description modified from de Lange (2014).

References and further reading

de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington.

de Lange, P.J. 2014: A revision of the New Zealand Kunzea ericoides (Myrtaceae) complex. Phytokeys 40: 185p doi: 10.3897/phytokeys.40.7973.

This page last updated on 1 Sep 2014