Quick Facts

Quick facts

• Rubber Vine (Cryptostegia grandiflora) is a shrubby plant or climber that grows rapidly and smothers other plants, often completely dominating the vegetation.
• It spreads aggressively from waterways into adjoining open woodlands and pastures and also threatens to choke the waterways and vine forests of northern Australia.
• Rubber Vine was estimated to cost the Queensland beef industry $18 million per annum in 1995.
• Its westward spread must be prevented to protect environmental and economic interests in the Northern Territory and northern Western Australia.
• Existing control techniques (chemical, mechanical, biological and fire) should be integrated for maximum effect.

What Does It Look Like?

What is it?

Rubber Vine (Cryptostegia grandiflora) is a robust woody shrub or climber. Without support it grows into a multi-branched shrub 1 to 3 m tall, but as a climber it can reach a height of up to 30 m when growing over other vegetation. The stems are greyish-brown in colour with warty spots (lenticels) and exude milky sap when broken. There are two different types of stems produced: branched stems with many leaves (up to 2 m long); and longer unbranched stems (called 'whip' stems) 3 to 8 m long that either find a support, or fall to the ground under their own weight and produce leafy side-branches.

The thick and leathery leaves are oppositely arranged along the stems and are dark green and glossy on the upper surfaces, with slightly paler and duller undersides. These leaves are hairless and are borne on reddish-purple stalks 5 to 20 mm long. The leaf blades (3 to 10 cm long and 2 to 6 cm wide) are ovate or oblong in shape with entire or slightly wavy margins.

The purplish-pink to whitish flowers (usually pale pink with a darker centre) are large and showy (4 to 6 cm long and 5 to 9 cm wide). They are funnel-shaped and have five broad petals that are partially fused into a tube, forming a trumpet shape. These flowers are borne on short thick stalks 4 to 8 mm long and occur in small clusters at the ends of the branches.

The pod-like fruit are produced in opposing pairs. These fruit (10 to 15 cm long and 2 to 4.5 cm wide) are greenish or brownish in colour, somewhat three-angled in cross-section, and contain 200 to 450 seeds. The seeds (5 to 10 mm long and 1.5 to 3 mm wide) are brown, flattened, and are topped with a silky tuft of white hairs 18 to 40 mm long (Navie 2007).

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

Flower colour

Pink

Growth form (weed type/habit)

Vine, Shrub

Where it currently grows? Preferred habitat

Rubber Vine is a weed of semi-arid, tropical and sub-tropical environments. It infests creek banks and other waterways (i.e., riparian zones), open woodlands, grasslands, closed forests, forest margins, pastures, roadsides, disturbed sites and waste areas. It prefers sites with ample moisture and low shrubs or trees to support its climbing stems (Navie 2007). Rubber Vine grows on all soil types and is currently restricted to areas receiving an annual rainfall between 400 and 1400 mm. Its seeds readily germinate on riverbanks and in other moist areas. The young plants rapidly grow over and smother other plants, often completely dominating the vegetation. It then spreads aggressively from the riverbank to adjoining open woodlands and/or pastures (CRC 2003).

Are there similar species?

Rubber Vine is very similar to Purple Rubber Vine (Cryptostegia madagascariensis), which has also occasionally become naturalised in northern Australia. Purple Rubber Vine can be distinguished by its yellowish-green or whitish coloured leaf stalks, its darker pink or purplish flowers and its shorter fruit (less than 10 cm long) (Tomley 1998; Doak and Deveze 2004).

Australian Rubber Vine (Gymnanthera oblonga) also has a similar habit and grows in the same areas of northern Australia. However, it can be easily distinguished by its much smaller greenish-yellow flowers (less than 2 cm long) and narrower fruit that are only 5-6 mm wide (Doak and Deveze 2004; Navie 2007).

Why Is It A Weed?

What are its impacts?

Rubber Vine is a Weed of National Significance and is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts. It grows rapidly and smothers other plants, often completely dominating the vegetation and spreading aggressively from waterways into adjoining open woodlands and pastures.

Rubber Vine has significant impacts on the pastoral industry and conservation areas in north-eastern Australia. Its main impact on pastoralism is the loss of grazing country, which in 1995 was estimated to cost the Queensland beef industry $18 million (CRC 2003). It is toxic to livestock and dense infestations replace productive species, rendering grazing country less productive or even useless. It also increases the costs of mustering and fencing.

Rubber Vine threatens waterways, woodlands and rainforests throughout north-eastern Australia, including significant conservation areas such as the Wet Tropics World Heritage Area and Cape York Peninsula. It is particularly invasive in riverine vegetation, and can potentially displace the plants and animals that inhabit riverbanks, thereby affecting the water quality of streams. The whole ecological integrity of the native vine thickets and riverine systems of northern Australia is under threat from Rubber Vine (CRC 2003).

How does it spread?

Rubber Vine reproduces mainly by seed, with each seed pod producing between 340 and 840 seeds, with about 95% of these seeds usually being viable. The seeds are scattered short distances from the parent plant by wind that catches the tufts of hairs on their ends, or longer distances by floating on water. Seeds may also be spread by birds, or in mud attached to vehicles, machinery and animals (CRC 2003). Rubber Vine has probably also spread in dumped garden waste (Navie 2007).

What is its history in Australia?

Rubber Vine was introduced into Australia as an ornamental and was first planted in the gardens of mining towns of northern Queensland in the late 1860s. Weedy infestations of Rubber Vine were reported by 1917. During the Second World War, Rubber Vine was also cultivated as a potential source of rubber, contributing to its spread (CRC 2003).

How To Manage It?

Best practice management

Biological, chemical, fire and mechanical methods are all used to control Rubber Vine. Check with your local council or state/territory government agency about its requirements for Rubber Vine control.

Chemical control: Herbicides are effective in the control of Rubber Vine, but their use is expensive when large areas are to be controlled. The strategic use of a range of registered herbicides is an effective method of controlling isolated or outlying Rubber Vine plants. Foliar spraying the entire plant from the ground and aerial spraying are most effective on smaller plants. The basal bark and cut stump techniques are more labour intensive, but are much more effective on more mature plants. All of these techniques should only be conducted when Rubber Vine is actively growing and are also less effective if plants have been damaged by biological control agents (CRC 2003; Land Protection 2006).

Non-chemical control: Fire can be an especially valuable and inexpensive part of an integrated Rubber Vine control program because it kills surface seeds, seedlings and adult plants. If there is sufficient fuel, Rubber Vine can be burnt whilst green with good success. In a fire research experiment west of Chillagoe in Queensland, 80% of the Rubber Vine was killed in an initial fire, with a follow-up burn one year later resulting in a 99% kill rate. The fuel load should be about 1500 kg per hectare and pasture may need to be spelled before burning to allow the fuel to accumulate to high enough levels (CRC 2003).

Blade or disc ploughs and cutter bars provide reasonable control of Rubber Vine, but are most often used to penetrate very dense infestations to allow easier access, or to open up the canopy. Mechanical control is not suited to areas such as gullies and creeks because it can lead to erosion. Recent research has shown that the use of fire after biological control agents have already damaged the plants can be highly effective. However, control programs should be tailored to the location, size, intensity and age of each situation (CRC 2003).

Biological control: Two biological control agents have become widespread in Queensland, since their release in the early 1990s and they have had an impact on the vigour of Rubber Vine. Rubber Vine Rust (Maravalia cryptostegiae) forms on the underside of leaves and causes them to turn yellow and drop and rust is usually abundant during the wet season but is less active during the dry season. The other agent is the Rubber Vine Moth (Euclasta whalleyi), whose caterpillars feed on Rubber Vine leaves between March and October. Both agents, especially the rust, can cause significant damage, but their effectiveness varies according to climatic conditions (CRC 2003; Land Protection 2006).

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

For further information see the Rubber Vine Management Manual (available at https://www.weeds.org.au/WoNS/rubbervine/ )

Does it have a biological control agent?

YES. Two agents released: the leaf feeding moth (Euclasta whalleyi), and the rubber vine rust (Maravalia cryptostegiae) (Harvey,  et al 2023).

When does it grow? (lifecycle/growth calendar)

Rubber Vine seedlings can flower shortly after the first year of growth under normal conditions in northern Queensland. Although it can flower at almost any time of the year, most flowering takes place during summer. Seed pod formation usually occurs from summer through to late autumn. The seed pods eventually dry out and are ripe after about 200 days, when they split open and release the seeds. Germination occurs following good rain. Seeds usually require between 5 and 15 days of exposure to moist, warm (20 to 30 ºC) conditions before they will germinate. Rubber Vine plants are thought to live for up to 80 years (CRC 2003).

Where Is It Found?

Which states and territories is it found?

WA, QLD

What areas within states and territories is it found?

Rubber Vine is widely naturalised in the north-eastern parts of Australia. It is particularly widespread and abundant in the northern parts of Queensland, less common in the central regions of Queensland and relatively rare in the south-eastern parts of this state (Navie 2007; Bostock and Holland 2007). It is particularly common throughout the river systems of southern Cape York, the Queensland Gulf country, central Queensland and south along the east coast to the Burnett River. Isolated infestations have been found as far south as Gatton (west of Brisbane) and as far west as the Northern Territory border. Infestations have also been located at Mt. Isa, Longreach, Blackall and Charleville (Mackay 1996). In 1991 the total area of Rubber Vine infestation was estimated at over 700,000 hectares of tropical and sub-tropical Queensland, although it was present over an area 50 times as large. Two infestations were also found in northern Western Australia in the 1990s, but these have since been controlled (CRC 2003).

Based on its climatic requirements, Rubber Vine has a potential distribution covering all of northern Queensland, the northern parts of the Northern Territory and most of the Kimberley and Pilbara regions of Western Australia. Parts of north-eastern New South Wales could also be affected (CRC 2003).

Where does it originate?

Rubber Vine is native to south-western Madagascar (Klackenberg 2001).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

YES

Where is it a declared weed?

Declared in all states and territories

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

Cryptostegia grandiflora

Other scientific names (synonyms)?

Nerium grandiflorum Roxb.

Does it have other known common name(s)?

Rubbervine, India Rubber Vine , India Rubbervine, Palay Rubbervine, Purple Allamanda