A glossy, trumpet-flowered climber planted in the 1860s has turned northern Queensland’s landscape into a toxic thicket. The plant, native to Madagascar, now blankets creeks and climbs 30 metres into tree canopies. It doesn't just grow; it smothers. By 1991, a single infestation zone covered an estimated 700,000 hectares. That’s a million football fields of native forest, replaced by a wall of greyish-brown stems and poisonous sap.
The invasion started quietly in the gardens of mining towns. By 1917, reports of infestations were filtering through. During World War II, farmers grew it as a rubber source. That decision accelerated its spread across the Gulf of Carpentaria coast, down to Bundaberg, and west to the Northern Territory border. It’s not just a weed. It’s a biological barrier.
Identifying it is easy if you know what to look for. The leaves are dark green, glossy, and paired. The flowers are large, pink or white, and trumpet-shaped. But the real danger lies in the seed pods. They are rigid, triangular, and up to 12 centimetres long. Each pod holds up to 840 seeds, each covered in silky white hairs. A single hectare produces millions of these seeds annually. Ninety-five per cent of fresh seed is viable.
The ecological cost is severe. The vine forms dense thickets that block waterways, reducing biodiversity and water quality. For graziers, the impact is immediate and painful. Thick infestations make mustering cattle nearly impossible. The plant poisons livestock and native animals, stripping them of food and shelter. It’s a slow, green chokehold on the region’s agricultural and ecological health.
Containment is the only path forward. The New South Wales Department of Primary Industries and Regional Development, via its WeedWise service, urges landowners to monitor and report infestations. The plant spreads via wind, water, and floating pods. Saltwater doesn’t kill it; seeds survive more than a month in brine. Without aggressive management, the 700,000-hectare footprint will only grow.