Leptospermum scoparium var. incanum
Common name
mānuka
Synonyms
None
Family
Myrtaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Trees & Shrubs - Dicotyledons
Chromosome number
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 | At Risk – Declining | Qualifiers: DP
2009 | Not Threatened
2004 | Not Threatened
Brief description
Small prickly shrub or small tree with flaky bark and hairy new growth and bearing masses of oval pointed leaves and, usually pinkish red-centred flowers. Endemic to northern Northland. Leaves rigid, 10-15 mm long by 1-2 mm wide, prickly to grasp. Flowers to 20mm wide. Fruit a dry 7-8 mm wide capsule.
Distribution
Endemic. Confined to the upper Northland Peninsula where it is abundant from Te Paki to Ahipara, and thence along the eastern coastline to Whangaroa. South of these stations it is locally present in mainly coastal shrublands, dunefield but also in some inland gumland scrub habitats. Exact southern limits are not, as yet clear.
Habitat
Abundant in coastal situations, especiallty dunefield, associated shrublands, gumland and on the margins of peat bogs.
Features
Shrub or small tree up to 5 m in height. Bark grey, peeling in long flakes, which become curled, and papery with age. Wood red. Branches numerous, arising from base, often suckering when covered in sand, and/or sprouting adventitious roots. Young branches, young leaves and flower buds clad in long silky, grey hairs. Leaves leathery (almost woody), very dark green, becoming subglabrous, narrowly lanceolate 10-15 x 1-2 mm, apex drawn out into a long stiff, sharp point, midrib not especially obvious, leaf margin finely crenate. Flowers solitary in leaf axils, up to 20 mm diam. Receptacle red or pink. Petals usually flushed pink or wholly pink, occasionally white or dark red. Stamens numerous. Capsule, long persistent and woody, 7-8 mm. Seeds numerous, straw-like, compressed 2.0 x 0.3 mm.
Similar taxa
Easily distinguished from all other New Zealand and Australian forms of L. scoparium by the erect shrub habit, silky hairy leaves and stems, dark pink or pink flushed flowers, and by the very large capsule which scarcely opens except after fire or the death of the plant.
Flowering
Throughout the year but with a peak in late winter early spring.
Flower colours
Red/Pink, White
Fruiting
The capsules are long persistent so invariably mature plants 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 seriously threatened, though some stands are at risk from clearance for farmland or through felling for firewood. However, the recent (2017) arrival of myrtle rust (Austropuccinia psidii) may pose a more serious threat to Leptospermum (see below).
Etymology
leptospermum: Slender seed
scoparium: Like a broom
Where To Buy
Occasionally cultivated. One cultivar known as ‘Cheryl Lee’ was popular in gardens, and commonly sold by garden centres for a while during the 1980s. Extreme pink-flowered forms from the Karikari Peninsula may be the basis for some of the cultivars now popular. Leptospermum scoparium ‘Keatleyi’ seems to be an early wild selection of this variety.
Myrtle Rust Threat
Myrtle rust (Austropuccinia psidii) was first detected in New Zealand in 2017. As there is as yet no known effective treatment for that rust. Overseas indications are that this rust is having a serious impact on Myrtaceae worldwide, including causing such severe declines in some that extinction of some species and genera seems inevitable. As such the New Zealand Threat Listing Panel elected to list all indigenous Myrtaceae using the ‘Precautionary Principle’ as ‘Threatened’ (de Lange et al. 2018). Hopefully this assessment will be proved wrong. As of 2018 there have been very few occurrences of myrtle rust on Leptospermum. However, the rust is still in its early establishment phase. Australian experience suggests it may take 10 or more years to truly establish which New Zealand Myrtaceae will be most affected. More information about myrtle rust can be found at myrtlerust.org.nz
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 1 February 2004. Description by P.J. de Lange.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Leptospermum scoparium var. incanum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/leptospermum-scoparium-var-incanum/ (Date website was queried)