How are seeds generally dispersed?

Many plants have seeds. The seeds of different plants differ in shape, size, color, surface texture and so on, but they all share one characteristic: they can reproduce. To reproduce, they must be dispersed. So, how are seeds dispersed?

There are many ways seeds are dispersed, such as self-dispersal, wind dispersal, water dispersal, bird dispersal, mammal dispersal, insect dispersal and so on. Among them, self-dispersal relies on the plant itself and does not depend on any other dispersal agent.

1. Self-dispersal

This relies on the plant itself and does not depend on any other dispersal agent. The seeds themselves have weight, and after ripening, the seeds fall directly to the ground due to gravity, such as the velvet apple and the big-leaf planchonella; some seeds' fruits split open after ripening and fling the seeds out, such as the African impatiens, the orchid tree, the Hong Kong orchid tree and bean pods.

2. Wind dispersal

Some seeds grow appendages shaped like catkins or feathers and ride the wind, such as the oriental false hawksbeard, the willow and the kapok; some tiny seeds have a relatively large surface area-to-weight ratio, so the seeds can drift with the wind and be carried far away, such as the dandelion.

3. Water dispersal

The surface of this type of seed is waxy and does not absorb water, the fruit skin contains air chambers, and the specific gravity is lower than that of water, so they can float on the water surface and be dispersed via streams or ocean currents. Because the seed coat of such seeds often has abundant fibrous material, it can prevent the seeds from rotting or sinking due to soaking and water absorption. Such as the water lily, the coconut, the box fruit tree, the lan fern and the terminalia.

4. Bird dispersal

Most of these seeds are fleshy fruits. Birds peck at the fruits, and because the seeds are not easy to digest, they are often excreted with the droppings, or the seeds are simply spit out.

5. Mammal dispersal

The seeds stick to the bodies of animals, or to the animals' food, and when the animals move, the seeds are dispersed.

6. Insect dispersal

This means relying on insects (bees, butterflies, moths, flies, ants, etc.) to disperse the seeds.