Weeds in Australia


Miconia spp.

 In Australia three species of Miconia are currently known from Queensland - M. calvescens, M. racemosa and M. nervosa. M. calvescens is considered as potentially the most problematic of the species (NRW 2005).

Miconia are evergreen trees which are commonly 4 to 8 m tall but can grow to about 16 m tall in favourable conditions. Young stems are greenish but become brown with age. The leaves, which are alternately arranged, can be extremely large. They are often about 7 to 15 cm wide and 17 to 30 cm long but can be up to 70 to 100 cm long in M. calvescens. The leaf blades are usually green above and distinctively purplish below with 3 very prominent veins which run from the base to the tip. The white or pinkish flowers are numerous, small and borne in large, branching clusters. The short-lived flowers give rise to fleshy, black, bluish-black or purplish berries which are about 6 to 7 mm in diameter. Individual berries contain 140 to 230 seeds, each of which is about 0.7 mm long and 0.5 mm wide (Navie 2004; PIER 2007).

For further information and assistance with identification of Miconia contact the herbarium in your state or territory.

Distribution:Miconia is only known as a naturalised species in a few locations in northern Queensland, in and around Cairns, Mossman and Kuranda (Navie 2004). 11 active infestations of M. calvescens were known in 2006 (Galway 2006).

It has the potential to spread over much of coastal, tropical north Queensland (Csurhes & Edwards 1998).

Key points:
  • Miconia (Miconia spp.) has the potential to cause irreversible damage to Australia's rainforests.
  • Under favourable conditions Miconias are capable of rampant growth and will form dense, monospecific thickets which will exclude native plants.
  • If naturalised plants are left to grow, it is expected that berries will be rapidly spread in Australia by fruit-eating birds.
  • Large, well-established trees are estimated to be capable of producing 3 million seeds, perhaps two or three times a year, and seeds may remain viable in the soil for more than six years.
Miconia is subject to an active eradication program in Queensland.
How it spreads:Miconia is generally spread by fruit-eating birds with birds such as the silver-eye expected to be vectors of the fruit. Seed is also known to be spread in mud on boots, earth-moving equipment and vehicles. Other dispersal agents include water and small mammals. Vegetative reproduction via layering (when a portion of an aerial stem grows roots while still attached to the parent plant and then detaches as an independent plant) and re-sprouting also sometimes occurs (Loope 1997; Csurhes & Edwards 1998).

Where it grows:Miconia is a potential weed of tropical and subtropical environments that invades closed forests, rainforest margins, creek-banks and disturbed sites (Navie 2004).

Flower colour:White, Pink
Distribution map: http://www.chah.gov.au/avh/index.jsp 

See also Navie S. (2004). Declared Plants of Australia. An identification and information system. Centre for Biological Information Technology: Brisbane. [CD-ROM]

Impacts:Miconia is an aggressive, invasive weed. In Tahiti, Miconia (specifically M. calvescens) forms dense, monospecific stands, covering 65-70% of the island. It poses a serious threat to half of the endemic plant species of French Polynesia. Miconia is currently growing on the margins of north Queensland rainforests and has the potential to spread in remote areas. It is well suited to the climate of coastal north Queensland and represents a serious threat to coastal tropical and tropical rainforests. If allowed to become firmly established it could form extensive, monospecific stands, displacing native flora and fauna and creating deep shaded which prevents regeneration of native plants (Loope 1997; Csurhes & Edwards 1998; Galway 2006; Meyer 2006).

The tentacular root system is also suspected to favour soil erosion and landslides (Meyer 2006).

Origin:Miconia is native to tropical America, ranging from about 18° N in Mexico to about 26° S in Brazil. It is now established in New Caledonia, Tahiti, Hawaii, Jamaica, the Galapagos, Sri Lanka and Australia (Loope 1997; Csurhes & Edwards 1998; PIER 2007).

History:Miconia has spread from its native range following its deliberate introduction as an ornamental. Due to its attractive foliage, it has been grown in European glass houses since the mid-nineteenth century. It was imported into the Townsville Botanic Gardens in 1963. It is grown in both public and private collections and is grown commercially by a small number of specialist nurseries from northern coastal New South Wales and northern Queensland (Loope 1997; Csurhes & Edwards 1998; Meyer 2006).


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This database is designed to provide information, including biological and ecological, on invasive plant species that are on a national weed list, or are legislated against in a state or territory. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. For further information on the images contained in the database please contact the copyright owner. All images in the weed identification tool are managed by the Australian Plant Image Index (APII). Various copyright conditions apply for these images. For further information on the copyright conditions of images contained in the database please contact the APII at: photo@anbg.gov.au.