Pods of certain plants such as gorse and pansies have a way of flinging their seeds when ripe in every direction with considerable force. The thing that helps these seeds disperse is first and foremost the mechanical force itself used to catapult the seeds.
As they ripen, the seed pods gradually lose moisture, building up tension in their cells and subsequently in the pod as a whole. The structure inevitably fails gradually and during a hot day it gives way altogether due to heat stress and triggers an explosion firing the seeds with appreciable force away from the parent plant almost like a projectile for up to 100m (300 ft) away.
It is important to note that plants which use this explosive method or ballistic dispersal as it is also called tend to have seeds that are generally large and too heavy to be carried by the wind unlike those of plants such as dandelions which are light enough for wind dispersal. Therefore gorse and suchlike plants employ ballistic methods to ensure their seeds travel as far away from the parent plant as possible.
