Methods of Seed Dispersal ECI 530 Dorothy Wambold

Project Description • This presentation provides an introduction to the various types of seed dispersal. • Four main methods of dispersal will be presented, along with examples of seeds that utilize those methods.

Menu - Methods of Seed Dispersal Animals and Humans Water Splitting Wind

Dispersion by Animals and Humans • Seeds with sticky hairs, bristles, hooks, or barbs are transported by sticking to the fur of animals or on the clothing of human beings. • Birds and other animals eat the fleshy fruits and discard the seeds, or they may eat both but the seeds are not digested and are passed out with their droppings.

Dispersion by Animals and Humans - Examples • Beggar-Ticks: Sticky, flat, seed-like fruits with tiny hooks that readily cling to the fur of animals and clothing of humans, thus promoting their spread far and wide.

Dispersion by Animals and Humans - Examples • Several fruits are eaten by humans and animals, and the seeds are discarded away from the parent plant. • Some of these fruits include blackberries, cherries, papayas and tomatoes.

Dispersion by Water • The fruits of most water plants have buoyant, waterproof coverings that allow them to float and disperse their seeds by water.

Dispersion by Water - Examples • Coconut: A coconut has a smooth outer rind, a fibrous husk and a stony central layer pitted with 3 small 'eyes' of soft tissue, through one of which a young shoot and root will emerge at germination. The rich supply of food and water in the coconut enables it to last for a long time on its watery journey.

Dispersion by Water - Examples • Lotus: The fruit is a conical-shaped pod filled with seeds, each seed in its own socket or hole. When the seeds ripen, they become loose and when the pod tips down, the seeds are released into the water.

Dispersion by Splitting • Some fruits scatter their seeds by literally exploding. The pod dries and eventually bursts open, forcibly shooting the seeds several feet in all directions.

Dispersion by Splitting - Examples • Rubber: Each threelobed fruit contains three seeds, one in each lobe. When it ripens, it explodes into 3 pieces, while still on the tree, catapulting away the smooth seeds with their distinctive light brown patches.

Dispersion by Splitting - Examples • Witch Hazel: The flowers grow in feathery clusters. When ripe, the seeds are shot from their small woody capsules some distance away.

Dispersion by Wind • Some seeds are enclosed in wing-like husks (with one or two propeller blades) or fluffy coverings that help them drift some distance away from the parent plant.

Dispersion by Wind - Examples • Maple: The seeds fall to the ground spinning like the blades of a helicopter. The blades slow down its descent and allow the wind to carry the seed away from the parent plant.

Dispersion by Wind - Examples • Dandelion: The flower matures into a globe of fine filaments that are usually distributed by wind, carrying away the tiny fruit that contains the seed. This globe is called the 'blow flower' or 'dandelion clock', and blowing it apart is a popular pastime for children. The number of blows required to completely rid the clock of its seeds is deemed to be the time of day.

Additional Resources • This website shows animations of various seed dispersal methods. • Select this video to see more seeds dispersal in action!

Closing and Citations • Several images and content was provided at http: //www. vtaide. com/png/seeddispersion. htm. • How Seeds Disperse: Here, There, and Everywhere was obtained from http: //www. discoveryeducation. com/.