New study reveals the explosive secret of the squirting cucumber
A team led by the University of Oxford has solved a mystery that has intrigued scientists for centuries: how does the squirting cucumber squirt? The findings, achieved through a combination of experiments, high-speed videography, image analysis, and advanced mathematical modelling, have been published today (25 November) in The Proceedings of the National Academy of Sciences (PNAS).
The squirting cucumber (Ecballium elaterium, from the Greek 'ekballein,' meaning to throw out) is named for the ballistic method the species uses to disperse its seeds. When ripe, the ovoid-shaped fruits detach from the stem and eject the seeds explosively in a high-pressure jet of mucilage. This projectile launch -- lasting just 30 milliseconds- causes the seeds to reach speeds of around 20 metres per second, and land at distances up to 250 times the length of the fruit (around 10 m).
Until now, the exact mechanism of the squirting cucumber's seed dispersal -- and how this affects its reproductive success -- remained poorly understood. In the new study, researchers from the University of Oxford and the University of Manchester conducted a variety of experiments on Ecballium specimens grown at the University of Oxford Botanic Garden.
