Plants can go ballistic to disperse their seeds. Himalayan balsam rips its seed capsule apart in a split second when touched, catapulting the seeds up to 6.7 metres, which often then float away in nearby streams or rivers, spreading this pernicious weed far and wide.
The squirting cucumber uses its own rocket propulsion. Water pressure inside the cucumber builds up until a slight touch is enough to launch it into the air, squirting seeds and juice out through the hole where the cucumber had been attached to its stalk.
Sphagnum moss packs thousands of spores into a round capsule on top of a stalk. As the capsule dries out it collapses, squashing the air inside until the pressure blows off the capsule’s top. The spores fire out in less than a hundredth of a millisecond, at about 32,000 times the force of gravity and reaching 10cm high, enough to catch a breeze and float away.
The American dwarf mistletoe shoots its seeds out up to 20 metres using a bizarre pump-action heat gun. Just before the seeds are ready, the plant warms itself up by about 2C, triggering a gooey gel in the plant to expand and blast the seeds out.
