Seeds on the move
Seeds need to move away from the plant they came from, so that they can grow in a clear space with plenty of light. Some seeds travel on the wind, dandelion seeds, for instance, use 'parachutes' to travel, while sycamore seeds use 'propellers'. Other seeds have tiny hooks which attach to the fur of a passing animal (or to our trousers and sweaters) and get carried about in that way. Coconut seeds are covered with thick fibres, so that the seed floats, and they are carried by the sea from island to another. The liquid inside a coconut gives the young plant some fresh water, which it needs when it lands on a sandy beach and starts to grow.
Seeds young and old
Arctic lupin seeds trapped in the frozen ground have germinated almost 10 000 years after being shed. Living seeds have also been found in the tombs of ancient Egyptians. But willow seeds last only a few months.