Phormium tenax
Common name
Flax, harakeke, korari (maori name for inflorescence).
Synonyms
None
Family
Xanthorrhoeaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Monocotyledonous Herbs
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.
PHOTEN
Chromosome number
2n = 32
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.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous to New Zealand and Norfolk Island. A broad circumscription has been adopted here - many botanists feel that plants from the Chatham Islands could be distinguished at species rank from the mainland New Zealand species, other distinctive variants occur on the Three Kings and outer Hauraki Gulf Islands, and along the Kaikoura coast. Norfolk Island plants though uniform differ in subtle ways from the New Zealand forms of P. tenax. Further study into this variation is underway.
Habitat
Common from lowland and coastal areas to montane forest, usually but not exclusively, in wetlands and in open ground along riversides.
Features
Stout liliaceous herb, 1-5(-6) m tall. Leaves numerous, arising from fan-like bases. Individual leaves rather stiff at first, but becoming decurved, somewhat pendulous or “floppy” in upper half to a third, 1-3 x 50-120 mm, usually blue-grey (glaucous) or dark green, lamina margin, entire, somewhat thickened and pigmented black, dark red, pink, yellow or cream. Inflorescence 5(-6) m tall, somewhat woody and fleshy when fresh, long persistent, drying charcoal grey or black, with the fibrous interior becoming progressively more exposed. Peduncle 20-30 mm diam., erect, dark grey-green or red-green, glabrous. Flowers 25-50 mm long, tubular, predominantly dull red but may also be pink or yellow; tips of inner tepals slightly recurved. Ovary erect. Capsules 50-100 mm long, dark green, red-green or black, trigonous in cross-section, erect, abruptly contract at tip, not twisted, initially fleshy becoming woody with age, long persistent. Seeds 9-10 x 4-5 mm, black, elliptic, flat and plate-like, margins frilled or twisted.
Similar taxa
Could only be confused with the so called mountain flax (Phormium cookianum) from which it is easily distinguished by the erect rather than pendulous seed pods
Flowering
(September-) October-November (-January)
Flower colours
Red/Pink, Yellow
Fruiting
(November-) December (-March)
Propagation technique
Very easy from fresh seed. Most commonly grown by the division of rooted fans from established plants.
Threats
Not threatened although see the discussion below about flax dieback. This die back phenomenon is characterised by abnormal yellowing of the leaves and may result in collapse of flax plants or whole populations.
Etymology
phormium: Basket or basketwork
tenax: Tough
Where To Buy
Very commonly cultivated throughout New Zealand and in many parts of the world. However, most cultivated material available is a mixture of hybrid, variegated and/or colour mutations. The actual wild forms of the species are now rarely available in mainline garden centres and nurseries.
Cultural Use/Importance
Harakeke is an important plant used in weaving. For more information go to the Weaving Plant Database run by Landcare Research. A report funded by the Sustainable Farming Fund identified numerous uses for flax to increase its abundance in the landscape including buffering or establishing corridors. For more information read “Integrating New Zealand Flax into Land Management Systems” by Elizabeth McGruddy (2006).
Flax Dieback
‘Yellow-leaf’ is one of the most serious diseases of harakeke (similar to the ‘sudden decline’ in cabbage trees). The disease is characterised by abnormal yellowing of the leaves. Scheele (1997) described how “growth of young leaves may be stunted and eventually the whole plant may collapse. Underground, the roots die off, the rhizome tissues collapse and rot spreads towards the crown of the plant”.
The cause has been identified as being a phytoplasma (a bacterium), transmitted by the native flax plant hopper. The hopper injects the bacterium into the leaf, while sucking the sap. Yellow-leaf is found in North and South Island, but is more prevalent in North Island (Boyce et al, 1951). For more information read “Integrating New Zealand Flax into Land Management Systems” by Elizabeth McGruddy (2006).
Attribution
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013)
References and further reading
Boyce, et al. 1951. Preliminary note on yellowleaf disease. NZJ of Science and Technology, 32(3): 76-77
Scheele, S. 1997. Insect pests and diseases of harakeke, Manaaki Whenua Press
Citation
Please cite as: de Lange, P.J. (Year at time of access): Phormium tenax Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/phormium-tenax/ (Date website was queried)