India, Oct. 10 -- You've probably walked past lantana without a second thought. With its tiny, brightly colored flower clusters, it appears to be a perfect garden plant. People grow it for its bright blooms, but may not consider how quickly it can spread. According to a 2012 PLOS One study by researchers at the University of Oxford, this shrub has become one of the worst weeds in recorded history. It got out of gardens in Australia and spread over the land. Queensland has paid a heavy price for that.

The plant is native to the American tropics. It reached Europe in the 16th century and has been bred for gardens ever since. That cultivation produced 630 named varieties and variants. The lantana that arrived in Australia shortly before 185...