Methods of seed dispersal

Plants disperse their seeds in different ways. Let us look at some of these ways:

Wind: Some plants depend on the wind to spread their seeds. These plants produce seeds that the wind can easily carry. They are light and are designed in a way that allows the wind to carry them away from their parent plant. Some of these seeds travel several miles before they land.

Dandelion seeds float away with the wind

Mahogany seeds spin around as the wind carries them away.

Water: Some plants depend on water to disperse their seeds. These plants often grow near the sea or on riverbanks. Their seeds are able to float. The seeds drop into the water and get carried away from the parent plant. Indian almonds and coconuts can be dispersed in this way.

A coconut can float hundreds of miles across the sea. It can then wash up on a beach and germinate.

The seeds of the indian almond tree can float across the sea and germinate somewhere far away from their parent plant.

Animals: Some plants produce seeds which can stick to animals. If an animal brushes against the plant, some seeds stick to its fur. The animal then carries the seeds away from the parent plant. The seeds fall off after some time in a new area where they may germinate.

Have you ever seen things like these stuck to your clothes? They contain seeds which may grow when they fall on the ground. (Photo by Anita Gould and used under a creative commons license)

Some plants, such as mango trees, produce fleshy fruits with large seeds. Animals eat the flesh of the fruit and throw away the seeds. The seeds may then grow into new plants. Other plants produce fruit with small seeds. When the fruit is eaten, the seeds pass through the digestive system of the animal but they are not destroyed. The seeds get passed out in the animal’s waste and can then germinate. Guava seeds and raspberry seeds are dispersed this way.

Can you see the tiny seeds in the guava? Birds, bats and other animals eat the fruit and spread the seeds in their droppings.

Mechanical: Some plants are able to fling or launch their seeds away from them. They do not rely on wind, water or animals to move their seeds. These plants have structures which cause their seeds to be thrown away from the parent plant. Mexican petunias, squirting cucumbers and some violets spread their seeds this way.

The mexican petunia produces seed pods. When they get wet they burst open and fling the seeds away from the plant.

Watch the video below of mexican petunia seed pods exploding.