Our Brisbane River versus ‘The Lilac Devil’ scourge

The Brisbane River has always been a vital transport corridor, linking neighbourhoods and carrying people across the city in their daily lives.

In the 1960s and ’70s, that routine was often disrupted when ‘The Lilac Devil’ came to visit.

Water hyacinth (Eichhornia crassipes), a South American waterborne weed – also known evocatively as the ‘The Lilac Devil’, due to its attractive purple-blue flowers – is one of the most invasive plants in the world.

Its dense root system and astonishing speed of propagation mean it can double in size week by week, given the correct conditions.

Once fully formed, it can destroy native animal and fish habitats by consuming huge amounts of oxygen and providing a breeding ground for mosquitoes.

Originally brought to New South Wales as an ornamental plant in the 1890s, the weed quickly spread from Sydney’s Royal Botanic Gardens up the east coast. By 1900, it had brought Ipswich’s bustling Bremer River to a standstill.

It reappeared for the next 70 years in creeks, lagoons and rivers all throughout Southeast Queensland.

‘The Lilac Devil’ would inevitably make its way to Brisbane – especially after storms and cyclones – arriving in extraordinary quantities in the city reaches, transforming parts of the river surface into a thick, drifting barrier. Items in State Library’s collections show the extent of the water hyacinth’s disruption.

One memorable 1908 photograph from Toowong Reach shows a young boy sitting on the weed like a stool: his boat was unable to move through the water.

For many living in Brisbane in the 1960s and ’70s, water hyacinth was a common feature of the river and remains a vivid memory.

Often entire sections would bloom overnight, turning the river into a carpet of green and purple.

Many more remember the smell of the weed after it was hauled out of the river.

A rare colour image of the infestation from the 1960s shows its enormous scale.

Were it not for the havoc it caused across Brisbane, it would have been a rather wondrous sight.

An often repeated (but likely apocryphal) story concerns a pair of brothers walking all the way from Bulimba to the Breakfast Creek Hotel across the weed carpet.

What was true was the dangers of sticking your hand or foot in too deep, with many local creepy crawlies finding the matted weed a particularly fine home.

Various methods of mechanical removal were used on the weed.

But none were truly effective on alarge scale.

Since 1975, the weed has been kept in check by introduced insect species and selective herbicides.

 If you have any photos of water hyacinth in Brisbane, contact qldmemory@slq.qld.gov.au