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Other Methods of Dispersal Dispersal using the Wind
Some carpels develop into fruits with thin wing-like structures attached to them. When these fruits are mature they break off the plant and, instead of falling straight to the ground, are taken by the wind. Their wing-like extensions cause them slowly to spiral their way down to the ground. In this way the wind moves them away from the parent plant. The sycamore, ash and maple all produce fruits of this type. In some fruits the carpels keep their styles and stigmas as they develop into fruits. The style and the stigma change into a type of feathery parachute which is blown away in the wind. The dandelion clock is made from hundreds of these parachute fruits, each containing a seed.
Poppies have fruits which develop into a dry capsule with little holes around the top. There are thousands of tiny seeds inside the capsule. The poppy fruit develops at the end of a long, flexible stalk. When this stalk sways in the wind, the seeds are shaken out of the capsule through the holes at the top. The seeds are so light that they remain in the air and move a long way from the parent plant before they fall to the ground. Dispersal using Water
This method of dispersal is used by many plants living near moving water but is not used by many land plants. Some coconuts fall into sea water and are washed up on the shores of tropical islands many thousands of kilometres away. Here, if the conditions are suitable, they may germinate into young palms.
Other Mechanisms
Some plants produce fruits called pods which contain rows of seeds inside them. When these fruits dry out the two sides of the pod suddenly separate, sometimes with such violence that t he seeds are thrown far away from the parent plant. Peas and lupins are two examples of plants that develop pods. This sudden separation sometimes produces a popping sound and this can be heard on the moor in late summer when there are broom and gorse bushes around. The squirting cucumber grows into a large fruit with its seeds floating in a liquid inside its thick skin. When the cucumber becomes too heavy for the plant, it falls to the ground. The pressure produced as it hits the ground forces the liquid containing the seeds out of one end of the fruit. The seeds are literally squirted away.
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