Species
Leptospermum scoparium var. scoparium
Etymology
Leptospermum: slender seed
scoparium: like a broom
Common Name(s)
manuka, tea tree, kahikatoa
Current Conservation Status
2012 - Not Threatened
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 - Not Threatened
2004 - Not Threatened
Authority
Leptospermum scoparium J.R.Forst. et G.Forst. var. scoparium
Family
Myrtaceae
Brief Description
Common small prickly shrub or small tree with flaky bark and more or less hairy new growth and bearing masses of oval pointed leaves and white or pinkish red-centred flowers. Leaves hard, 5-20mm long by 1-8mm wide, prickly to grasp. Flowers to 25mm wide. Fruit a dry 5-7mm wide capsule.
Flora Category
Vascular - Native
Structural Class
Dicotyledonous Trees & Shrubs
Synonyms
None - a myriad of varieties have been proposed none of which has been strictly synonymised within L. scoparium. Allan (1961) describes some of these, several may warrant further study.
Distribution
Indigenous to New Zealand and Australia. Most Australian forms of L. scoparium do not match the range seen in New Zealand. However, plants from Tasmania are very similar to, if not identical with some South Island forms, differing mainly by their wider leaf base, and longer, more pungent leaf apex. Manuka was also collected once from Rarotonga by Thomas Cheeseman in the 1800s. It has not been found there since, and is assumed to have been a failed introduction. Further study using DNA sequencing is underway to resolve the status of L. scoparium forms both here and in Australia.
Habitat
Abundant from coastal situations to low alpine habitats.
Features
Decumbent shrub, subshrub, shrub, or small tree up to 5 m in height and in decumbent forms 2-4 m across. Bark light grey to charcoal grey, peeling in long papery flakes, these curling with age. Wood red. Branches numerous erect, spreading or decumbent, arising from base, sometimes sprouting adventitious roots and/or layering on contact with soil. Young branches, young leaves and flower buds densely to sparingly clad in long silky, white hairs. Leaves leathery, pale to dark green, glabrescent to glabrous, linear-filiform, narrowly lanceolate, lanceolate, oblanceolate, to elliptic or obovate (5-)10-15(-20) x 1-2-5(-8) mm, invariably apex drawn out into a long stiff, pungent point, midrib usaully distinct sometimes obscure, leaf margin finely crenate, veins simple, scarcely branched. Flowers solitary in leaf axils, (8-)10-20(-25) mm diam. Receptacle dark red, crimson or pink. Petals white, sometimes flushed pink or dark red. Stamens numerous.
Similar Taxa
With the exception of L. scoparium var. incanum a broad circumscription of the the New Zealand forms of manuka (L. scoparium) has been adopted. In this sense, manuka could only be confused with kanuka (Kunzea ericoides sensu. lato) and Great Barrier Island kanuka (Kunzea sinclairii), from both of which it can be easily distinguished by the hard, persistent, circular, nut-like fruits, with non persistent sepals.
Flowering
Throughout the year
Flower Colours
Red / Pink,White
Fruiting
The capsules are long persistent so invariably mature plants always possess at least some capsules.
Propagation Technique
Very easy from fresh seed. Seed must be sown fresh, even if left for a few weeks before sowing viability can drop, especially if seed is allowed to dry out. Difficult from cuttings.
Threats
Not threatened, though some stands are at risk from clearance for farmland or through felling for firewood.
Chromosome No.
2n = 22
Endemic Taxon
No
Endemic Genus
No
Endemic Family
No
Life Cycle and Dispersal
Seeds are wind dispersed (Thorsen et al., 2009).
Where To Buy
Commonly cultivated. However many garden forms are horticultural selections based on crosses between L. scoparium var. incanum and white or red-flowered L. scoparium var. scoparium. Some seem to represent natural variations, others may stem for deliberate crosses with Australian forms of L. scoparium and allied species. Recently a number of Australian Leptospermum have been introduced into New Zealand, and these have been deliberately crossed with manuka.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 1 February 2004. Description by P.J. de Lange.
References and further reading
Gardner, R. 2002. Notes towards an excursion Flora .Manuka Leptospermum scoparium myrtaceae. Auckland Botanical Society Journal, 57: 147-149
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
This page last updated on 5 Jun 2015