Birds and mammals, including human beings play an efficient and important role in the dispersal of fruit and seeds.
They have the following devices.
1. Hooked fruit: The surface of the fruit or seeds have hooks (Xanthium), barbs (Andropogon), spines (Aristida) by means of which they adhere to the body of animals or clothes of human beings and get dispersed.
2. Sticky fruits and seeds:
- Some fruits have sticky glandular hairs by which they adhere to the fur of grazing animals.
Example: Boerhaavia and Cleome.
- Some fruits have viscid layer which adhere to the beak of the bird which eat them and when they rub them on to the branch of the tree, they disperse and germinate.
Example: Cordia and Alangium.
3. Fleshy fruits: Some fleshy fruits with conspicuous colours are dispersed by human beings to distant places after consumption.
