Seed dispersal

There are 3 main methods of seed dispersal.

1. Wind

2. Explosive

3. Animal

Mnemonic to remember some of the types of seed dispersion

A huge explosion (explosive) caused by the animals terrible wind dispersed the seeds.

Animal dispersal can be further divided into internal animal dispersal and external animal dispersal.

Examples

External animal dispersal

Seeds that are dispersed externally by animals use hooks or spines to cling onto the fur of animals as they brush past the plant. These then drop off later after the animal has moved on. Examples include burdock.

Seeds that are dispersed externally use hooks or spines to cling on the fur of animals these then drop off after the animal has moved, an example could be burdock

Internal animal dispersal

Seeds that are dispersed internally by animals use a fruit to entice the animal to eat the seeds. The seed coat protects the seed as it passes through the digestive system before being excreted by the animal. Examples include strawberries.

Seeds in fruit are consumed by the animal, the seeds outer surface can protect itself from digestive systems the seed is then excreted example could be a strawberry.

Wind dispersal

Seeds that are dispersed by the wind can take several forms. Common examples are dandelion seeds and sycamore seeds.

Seeds that disperse by wind can be varied but usually the seed creats a sail like structure that carries the seed away from the plant, common examples can be sycamore or dandelion seeds

Explosive dispersal

When ripe the seed pods of Himalayan balsam and exploding cucumbers will explode when they are touched, ejecting the seeds away from the parent plant.

When ripe seed pods such as the ones on himalayan balsam explode when touched ejecting the seeds away