1. What Adaptations Do Plants Have to Disperse Seeds?

2. Plants rely on their environment to disperse seeds.
Wind
Animal Transport
External
Internal
Other: burying seeds
Drop to ground

3. Wind Dispersal
Some structures allow seeds to be easily carried in the wind.
Achene
Pappus

4. Animal Transport
Some plants depend upon animals to disperse their seeds. There are three variations of animal dispersal:
External Transport
Examples of seed structures for external transport:
Hooks
Barbs
Internal Transport
Seeds are encased in fleshy fruits
Inadvertent dispersal (burying seeds)

5. Hooks and Serrated Edges
Projections extending from a seed case attach onto a passing animal, carrying the seed to a new location.

6. Barbs
Barbs attach to animal fur.
Barb

7. Internal Dispersal
Fleshy fruits surround seeds to be consumed and expelled by animals.

8. Other Animal Assisted Dispersal
The Oak tree depends upon the squirrel for its seed dispersal.
Squirrels bury acorns in the Fall and often forget where they are in the winter. These seeds then sprout new trees.

9. Drop Dispersal Some plants simply drop the seeds on the ground.
Individual seed
What are some disadvantages of this method?

10. What adaptations do seeds have to assist in dispersal?
Identify the adaptation and type of dispersal for each of the following pictures. 1 2 3 4 5

11. Answers 1 3 Composite: Pappus; wind Acorn: Food; animal dispersal 4 2
Wildflower: Drop dispersal
Wildflower: Hooks; animal dispersal 5
Composite: Pappus; wind

12. This is an individual seed case from the burdock bur taken at 60X.
Seed photos in this presentation were taken with the QX3 Intel Play Microscope.