Copper makes seed pods explode https://www.mpg.de/18774708/copper-makes-seed-pods-explode
Plants have evolved numerous strategies to spread their seeds widely. Some scatter their seeds to the wind, while others tempt animals and birds to eat their seed-filled fruits. And a few rare plants – such as the popping cress Cardamine hirsuta – have evolved exploding seed pods that propel their seeds in all directions.
„The link between these two findings is copper“, says Hay.