Students will learn how plants spread their seeds and populate new areas, and will be encouraged to think about plants as organisms that are (1) adapted to their environment and (2) contribute to the well being of other plant and animal species. (Adapted from Work House.)
Gradess: 4 – 6
Time Required: 1 – 2 hours
Subjects: Life science, social studies
Teacher Background:
Modern cultures tend to think about plants as organisms that are subject to the whims and uses of humans and other animals. Traditional Native American cultures have seen plants in a very different light. According to their perception, plants have spirits and are able to communicate among themselves and occasionally with other beings. Such a view of nature may be viewed as primitive by scientists and other “modern” people. Native Americans, however, are relating very personally with their environment. The intimacy of that relationship seldom, if ever, distorts the basic soundness of their understanding of plants. Their perspective certainly adds a more personal dimension to the study of plants. In fact, plants do have a number of defense mechanisms and many techniques for pioneering new living space.
Materials:
- Balloons (Green, brown, and red are preferable)
- Frozen or fresh berries (huckleberries, blueberries or raspberries are most appropriate, purple or red balloons will suffice)
- Grocery bags (preferably painted bright red, pink or white)
- A yellow or black stocking cap
- Powdered sugar
- Marshmallows
- Velcro strips
- A collection of locally gathered seeds such as dandelion, maple, poppy, cockle burrs, pine cones, and mushroom spores.
Procedure:
1. Discuss the concept that plants are rooted in the ground and spend their entire lives in one spot, but have active mechanisms with which to spread their seeds into new territory. It is through these mechanisms that plants were able to invade the barren areas of Waterton-Glacier International Peace Park as the ice age glaciers receded.
2. Choose a student to be a burr bearing plant. Explain that a burr is a seed designed to stick to animals that pass by. Mention that burrs were an inspiration for the invention of velcro (Natures Velcro). Show the students the velcro and burrs you’ve brought to class. Choose another student to be a large mammal that lives in W-GIPP. Give the plant an inflated balloon. Ask the student to rub the balloon against clothing to generate static electricity. The mammal comes walking down the trail, stops to scratch, and the plant places the balloon on the mammal’s back. The balloon stays attached until the mammal has traveled some distance. Eventually the seed drops by the wayside.
3. Choose another student to be a huckleberry plant. Have the student hold some berries while standing by the trail. Another volunteer becomes a grizzly bear and eats the berries. The grizzly continues on down the trail and deposits seeds complete with fertilizer. A purple balloon is not as much fun as berries, but is more graphic in the deposit demonstration. Did you ever wonder why huckleberries seem to line so many of the trails in the Park?
4. Have another student be a mountain maple tree. Have the student inflate a green balloon, tie it, and use the wind to transport it as far away from its parent as possible.
5. Have another student be a puffball. Have the student inflate a dark balloon and release it. The balloon will rocket out into the room and settle on the floor some distance away. Some plants and mushrooms use gases to propel their seeds or spores out away from the parent plant.
6. Select students to be a pine tree and a stream. Explain that conifers use several mechanisms for seed and pollen dispersal. Give the tree a green balloon and have the stream meander by. As the stream passes by the tree, the tree drops a cone into the open arms of the stream. The stream continues down its course and deposits the cone ashore some distance below. It is important that students understand that this is only one of several ways that conifers spread their seeds.
7. Discuss the relationships that flowering plants have with pollinating insects. Explain that this is the most sophisticated arrangement for pollination of flowers. (Before the presentation begins, sprinkle powdered sugar in the bottom of a colored grocery bag so that it sticks to the sides after shaking. Place a marshmallow in the bag with the sugar. Place another marshmallow in a second colored grocery bag without sugar.) Choose a student to represent a honey bee. Put the black or yellow stocking cap on the student’s head and say there is a treat in the first bag. Explain that bees use their proboscis to obtain nectar from flowers. Hold the bag (blossom) and have the bee get its treat. The bee must stick its head in the bag. In the process of gathering nectar (marshmallow) the bee will pick up a coating of pollen (powdered sugar) on its head (cap). Ask the group what the bee has on its head. Tell the bee that you have another treat in the other blossom. In the process of bobbing for more nectar (marshmallow) pollen (powered sugar) will be deposited in the other bag. Show the small amount of pollen at the bottom of the second blossom to the group. Discuss the importance of bees to the process of pollination.
Variations and Extensions:
Ask the students to explore their neighborhoods in search of various seeds and have them demonstrate and explain the mechanism for dispersal. Interesting seed variations are available during all seasons of the year. Have students choose a seed dispersal mechanism and report on plants using that method. Put the reports together in a class book on propagation methods in plants. Donate the book to the school library.
Assessment:
Have students write their own “why” story about a plant’s seed dispersal mechanism.
