What Adaptations Do Plants Have to Disperse Seeds?

Plants rely on their environment to disperse seeds. • Wind

• Animal TransportExternalInternalOther: burying seeds

• Drop to ground

Wind Dispersal

Some structures allow seeds to be easily carried in the wind.

Achene Pappus

•External Transport

Examples of seed structures for external transport:

•Hooks

•Barbs

•Internal Transport

•Seeds are encased in fleshy fruits

•Inadvertent dispersal (burying seeds)

Some plants depend upon animals to disperse their seeds. There are three variations of animal dispersal:

Projections extending from a seed case attach onto a passing animal, carrying the seed to a new location.

Barbs attach to animal fur.

Barb

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

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.

Some plants simply drop the seeds on the ground.

What are some disadvantages of this method?

Individual seed

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

2

3

4

5

1

Acorn: Food; animal dispersal

Wildflower: Hooks; animal dispersal

Composite: Pappus; wind

Wildflower: Drop dispersal

Composite: Pappus; wind

Answers

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.