Melaleuca quinquenervia (Cav.) S. T. Blake
Family: Myrtaceae Common name(s): broadleaf paperbark tree, broadleaf teatreeCategory: proposed 1a (NEMBA)
DescriptionPerennial evergreen tree, 12- 25 m tall, with pale cinnamon to whitish bark. Leaves grey-green, alternate, lanciolate to oblanceolate, apex acute, have smell of camphor when crushed. Inflorescences many-flowered, in dense spikes. Flowers are white to cream white, arranged in cylindrical brushes. Flowers throughout winter and autumn. Fruits small, woody, short cylindrical capsules.
DistributionBroadleaf paperbark tree is native to Australia, New Caledonia and Papua New Guinea. It has become naturalised in the Everglades National Park in Florida, where it is considered a serious invasive plant. It has also been recorded as invasive in Hawaii. This species has been introduced to several locations as watershed cover, to prevent soil erosion and for essential oil production plantations.
How it spreadBroadleaf paperbark tree spreads mainly by seeds. Seeds can remain viable within seed capsules for several years. A mature tree can produce more than a million seeds per annum. Seeds are tiny which makes them easily dispersed by wind or water, although germination occurs typically close to parent plants. It is highly flammable, and following fires, paperbark spreads vigorously.
History in South AfricaIt is not clear as to when the species was introduced into South Africa, but from preliminary observations by the EDRR team in the Western Cape Province at Waterval Nature Reserve, it seemed that the oldest plants may have been around for decades. It was probably introduced as an ornamental plant because of its interesting bark and showy flowers and for wind-breaks and hedging.
Environmental and economic impactsBroadleaf paperbark tree invades disturbed lands such as abandoned farm lands, natural forest, riparian zones, open swamps and wetlands. It rapidly colonises freshwater wetlands and almost completely displaces the native vegetation. This species destroys nesting grounds/habitat and reduces forage for prey species of birds. It is a highly problematic invasive in Florida in the US because of its prolific seed production and potential impact on human health and current annual expenditure on management is up to US$2.2 million. This species is listed as one of the 100 world's worst invasive alien species.
How to eradicateThere are no registered herbicides for this species in South Africa, although cut-stump treatment with imazapyr herbicide seems to be highly effective.
What can you do to help?Report sightings of these plants to the Early Detection and Rapid Responce Programme (EDRR) at SANBI. We will need to know its locality (the exact locality, supply any landmarks of GPS information if possible).
Contact detailsKanyisa NyafuEmail address: firstname.lastname@example.org Tel: 021 799 8762
- American Bird Conservancy. Melaleuca (Melaleuca quinquenervia). available on line at: http://www.abcbirds.org/conservationissues/threats/invasives/melaleuca.html. Accessed on 26/07/11
- Florida Exotic Pest Plant Council. 1991. Exotic Woody Plant Control, Ken Langeland, ed.
- Global Invasive Species Database. Melalueuca quinquenervia. Available on line at:http://www.issg.org/database/species/ecology.asp?si=45&fr=1&sts=&lang=EN. Accessed on 22/07/11
- Mazzotti, F.J., T.D. Center, F.A. Dray, and D. Thayer. Ecological Consequences of Invasion by Melaleuca quinquenervia in South Florida Wetlands: Paradise Damaged, not Lost. http://edis.ifas.ufl.edu/UW123. Accessed on 26/07/11
- Texas invasive database. Melalueuca quinquenervia.http://www.texasinvasives.org/plant_database/detail.php?symbol=MEQ. Accessed on 22/07/11
- Pacific Island Ecosystem at Risk (PIER). Melalueuca quinquenervia. Available on line at:https://www.hear.org/pier/species/melaleuca_quinquenervia.htm. Accessed on 22/07/11
Compiled by Thulisile Jaca