Quick Facts

Quick facts

• Miconia (Miconia spp.) are evergreen trees that commonly grow 4 to 8 m tall but can reach 16 m.
• Miconia 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.

What Does It Look Like?

What is it?

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 (fruit) 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.

Flower colour

White, Pink

Growth form (weed type/habit)

Tree

Where it currently grows? Preferred habitat

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

Are there similar species?

There are no other species in Australia, native or naturalised, that are similar to Miconia (Navie 2004).

Why Is It A Weed?

What are its impacts?

Native ecosystems: 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).

How does it spread?

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).

What is its history in Australia?

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).

How To Manage It?

Best practice management

Miconia is one of the species targeted for national eradication under the National Resource Management Ministerial Council's National Cost-Sharing Eradication Programmes. These programmes map and monitor the full distribution of the species, and coordinate or undertake activities to eradicate that species from Australia. If you think that you have found Miconia in Queensland then contact Biosecurity Queensland (https://www.daf.qld.gov.au/__data/assets/pdf_file/0004/69196/miconia.pdf).

Eradication appears to be achievable and an eradication campaign is currently being undertaken in Queensland by the Department of Natural Resources and Mines (Csurhes & Edwards 1998; NRW 2005).

Non-chemical control: Manual control: Hand removal of Miconia trees less than about 3 m tall is effective.

Chemical control: Larger trees which cannot be uprooted should be cut down and the stump treated with a herbicide to prevent re-sprouting (Loope 1997).

For more information on the problems of access, the use of aerial spraying of herbicides and type of herbicides in use in Hawaii see Loope (1997).

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Biological control: In Hawaii, since 1993, more than 70 species of potential biological control agents have been examined. However, even assuming best case scenarios, success of Miconia biological control is not a short-term option (Loope 1997).

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Flowering and fruiting begins after four to five years. In Hawaii flowering and fruiting of mature trees appears to be synchronized and may be triggered by weather events (drought and/or rain). A single tree can flower and fruit two or three times in a year. A single flowering or fruiting event is prolonged, with all stages of mature and immature fruits often seen on a single tree (Csurhes & Edwards 1998; Burton undated).

Miconia is a prolific setter of seed, with a healthy 10 m high tree estimated to be capable of producing 3 million seeds, perhaps two or three times a year. This results in a prolific seed bank. Greenhouse trials in Tahiti showed that a square metre of the top 2 cm of soil from a dense, mature stand of Miconia produced 17 808 seedlings in six months. The seed can germinate in dense shade although germination is usually stimulated by an opening in the canopy. Seeds can survive for more than 6-8 (perhaps more than 10) years in the soil. Plants can initially grow at a rate of about 1 m/year (Meyer 2006; Burton undated).

Where Is It Found?

Which states and territories is it found?

QLD

What areas within states and territories is it found?

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). Scattered infestations have also been found in northern New South Wales (QLD DAF 2020).

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

Where does it originate?

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).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NSW, NT, QLD, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Miconia spp.

Other scientific names (synonyms)?

Does it have other known common name(s)?

Bush Currant, Purple Plague, Velvetleaf, Velvet Tree