Grade Level: Elementary School; Type: Botany
This science project involves examining what happens to “explosive” seeds.
- What environmental factors trigger the release of seeds from seed pods?
- How far away to the released seeds travel? Do all seeds travel the same distance?
- Do seed pods from different plants release them in response to same stimuli?
Plants such as mistletoe, violets, primrose and pansies release their seeds into the air, often with substantial force. In this experiment, students will examine under what conditions individual plants release seeds and how far the seeds are released.
- Two to four different plants that release their seeds in the air. Pansies, wild geraniums, evening primrose and violets are good candidates, but others work well, too.
- Graph paper
- Tongue Depressor
- Purchase two to four different plants that shoot seeds into the air. Do some library research to identify when your plants produce seedpods and when the seedpods mature. Learn whether special conditions such bright sunlight, rain, or darkness are necessary.
- Set up the wine vane at the same height as the seed pods. If necessary, you can improvise a wind vane by tying a ribbon to a stick and anchoring the stick in the ground. This step is not necessary if you keep your plants indoors.
- Cover the area surrounding each plant with felt. Felt is desirable because the seeds will tend to stick more to the felt than they will to paper. How much felt you need depends upon the size of your plants. Be sure to have at least one yard of felt in all directions from the plant. Do not put plants immediately next to each other or you will have difficulties telling their seeds apart. A basement or garage floor may be ideal for this.
- Check your plants several times a day and examine their seed pods so that you know when the pods release their seeds. After the pods have released their seeds, make a record of the wind speed, time of day and distance that the seeds traveled. Draw a map, indicating approximate distances. Graph the distances against the number of seeds.
- Estimate the trajectory that the seed traveled.
- Determine whether there was a relationship between the seed shape and the distance traveled.
Terms/Concepts: Seed dispersal, explosive seed dispersal
- Marika Hayashi, Kara L. Feilich and David J. Ellerby. “The mechanics of explosive seed dispersal in orange jewelweed (Impatiens capensis).” Journal of Experimental Botany (2009).
- Countryside Info: Explosive Seed Dispersal