Quick Facts

Quick facts

• Harungana (Harungana madagascariensis) is a serious environmental weed of the wet tropics region of North Queensland, especially in the Babinda region.
• It is an invasive species from Madagascar that invades cyclone-damaged forest, forest fringes, roadsides, tracks, drains and riparian ecosystems.
• It forms dense thickets excluding other species.
• It has already begun to invade the rugged eastern slopes of the Bellenden Ker Range, and there are fears that it may become a permanent component of tropical rainforests.
• Harungana is a restricted invasive plant under the Biosecurity Act 2014 and must not be given away, sold, or released into the environment.

What Does It Look Like?

What is it?

Harungana (Harungana madagascariensis) is an erect multistemmed shrub or tree 4–20 m tall. The bark is rough and scaly and often vertically fissured. The young stems are covered in star shaped (stellate) hairs. Damaged or broken leaves and stems exude a brilliant orange sap (latex). The egg shaped leaves are 6–20 cm long and 3–10 cm wide, conspicuously dotted with black glands, and arranged opposite to each other on the stems. The upper leaf surface is dark green and glossy while the underside is densely covered in rusty coloured stellate hairs.

The flowers are arranged in dense many-flowered heads, 8–20 cm long, at end of main or side shoots. The small whitish or cream-coloured flowers are sweetly almond-scented and dotted with black glands.

The berry-like fruit (drupes), rounded and 2–4 mm across contain 2–4 seeds each. Initially orange to yellow-brown they turn deep-red to brown at maturity (Eggeling 1951; Dale & Greenway 1961; Robson 1961; Bamps 1970; Palgrave 1984; Keay 1989; Navie 2004; National Herbarium of Victoria 2007).

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

Flower colour

White

Growth form (weed type/habit)

Tree, Shrub

Where it currently grows? Preferred habitat

In its native range, Harungana occurs from 0-1800 metres (Robson 1961), in evergreen forest, forest margins, fringing forest in savanna regions, and in riparian (riverside) habitats (Palgrave 1984; Keay 1989), in regions with the annual rainfall of about 1000 mm or more (Robson 1961). It is a pioneer species, and one of the earliest colonisers of cleared forest, abundant in recent secondary growth (Palgrave 1984; Keay 1989).

In Queensland, Harungana invades cyclone-damaged forest, forest fringes, tracks, roadsides, drains and riparian habitats (Anon. 1995; Csurhes & Edwards 1998). It grows on well-drained soils and can withstand poor drainage on alluvium (Ward et al. 2001). It has assumed similar ecological niches as in its native range, and is restricted to areas with a similar rainfall as in its native range in Africa (Stajsic 2007, pers. comm.).

Are there similar species?

Harungana is fairly distinctive and unlikely to be confused with any other species occurring in Australia (Navie 2004).

Why Is It A Weed?

What are its impacts?

Native ecosystems: Harungana produces large numbers of seeds which germinate en masse, and rapidly establish themselves (Anon. 1995). It has invaded cyclone and logging damaged forest, forest fringes, roadsides, tracks, drains and riparian ecosystems (Csurhes & Edwards 1998; Anon. 1995; Vitelli & van Haaren 2001), forming dense thickets excluding native species, ultimately forming a monoculture over several hectares (Humphries et al. 1991; Humphries & Stanton 1992; Vitelli & van Haaren 2000), and destroying habitat for native fauna (Queensland Natural Resources and Water 2005a). Incursions have been discovered 2 ½ km into undisturbed rainforest, in small gaps created by tree falls and landslips (Anon. 1995).

Although the current incursions are mostly restricted to the Babinda region, there is a potential for the species to increase its range to other areas with favourable climate and rainfall in tropical Australia (Natural Resources and Water Queensland 2005b). One of the reasons for this is its broad elevation tolerance in its natural range in Africa, which varies from sea level to 1800 metres. There are fears that over the next 20–30 years the species may invade the higher peaks of the Wooroonooran National Park. It has the possibility of becoming a permanent component of tropical rainforests (Csurhes & Edwards 1998) with the majority of the wet tropics at risk of invasion (Vitelli & van Haaren 2001).

How does it spread?

Harungana produces a large quantity of seeds, which may be dispersed by fruit-eating birds, fruit-bats, water and machinery (Vitelli & van Haaren 2001; PIER 2003; Anon. 1995). It may also spread laterally via the development of suckers from its roots (Navie 2004).

What is its history in Australia?

It is unknown how Harungana was introduced to Australia (Vitelli & van Haaren 2001; Bean 2007, pers.comm.). It may have originally being introduced as a garden plant in the Babinda region (Anon 1995) or possibly for medicinal use (Queensland Coalition undated) but there is no concrete evidence for this. The earliest specimen of Harungana held at the Queensland Herbarium was collected on 25 September 1937, and there is no information on the specimens which indicates the mode or reason for the introduction (Bean 2007, pers.comm.).

How To Manage It?

Best practice management

There is little information available in relation to the control of Harungana. Control appears to be limited to either physically hand pulling or digging out seedlings and young trees or applying herbicide treatment (Vitelli & van Haaren 2001; PIER 2003).

Chemical control: Trees can be cut down, and the stumps should be treated with herbicide (PIER 2003). For regrowth (and presumably seedlings/saplings), foliar applied herbicides may be a cost effective option. For trees, the stem injection method may be the preferred option (Swarbrick 1993; Vitelli & van Haaren 2001). Treating plants with herbicide prior to flowering will also reduce flowering and hence fruit production (Vitelli & van Haaren 2001). A list of chemicals that can be used on Harungana can be found here https://www.daf.qld.gov.au/__data/assets/pdf_file/0010/66457/harungana.pdf.

The rugged terrain of much of the Wet Tropics exacerbates the efforts required in detecting, controlling and monitoring incursions. Many areas are very difficult to access, and accessible only by foot, or four wheel drive motorbikes, or canoes and boats (Setter & Vitelli 2003).

Ongoing monitoring and follow up is an essential part of control (Stajsic 2007). An eradication program in the late 1990s treated approximately 60 % of the known incursions, by using the stem injection. However, the failure to follow-up on regrowth now sees it infesting many ridges and wherever storm damage has broken the forest canopy (Vitelli & van Haaren 2001).

Any control should avoid mechanical disturbance to the site, which encourages seed germination.

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

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

In North Queensland, flowering has been recorded between August and November (National Herbarium of Victoria 2007; Bean 2007, pers. comm.), with the peak flowering time been in October and November (Vitelli & van Haaren 2001). Fruits are produced between October and December (Bean 2007, pers. comm.).

Where Is It Found?

Which states and territories is it found?

QLD

What areas within states and territories is it found?

Harungana has a restricted distribution in Australia, centred on the Babinda area in the 'wet tropics' region of coastal, north Queensland (Humphries & Stanton 1992; AVH 2007), particularly the lower slopes of the Bellenden Ker Range and the western slopes of Graham Range. Outlying populations occur south to Bramston Beach and Miriniwinni (Vitelli & van Haaren 2001). It has also spread to the inaccessible terrain of the eastern slopes of the Bellenden Ker Range (Goosem 2003). It has also been recorded from south-east Queensland (Navie 2004) but these are cultivated trees and have not naturalised.

Although the current incursions are mostly restricted to the Babinda region, there is a potential for the species to increase its range to other areas with favourable climate and rainfall in tropical Australia (Natural Resources and Water Queensland 2005b).

Where does it originate?

Harungana is native to tropical Africa, Madagascar and Mauritius (GRIN 2007).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

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

Harungana madagascariensis

Other scientific names (synonyms)?

Does it have other known common name(s)?

Dragon's-blood Tree, Haronga, Orange-milk Tree, Praying Hands Bush, Praying Hands