FOCUS: Grasses are hardy plants that grow over much of the earth, flourishing in harsh conditions. They are able to withstand high winds, hold onto slippery slopes, and grow back after being mowed, burned or grazed. Grasses have fascinating and unique adaptations that make them extremely resilient and set them apart from other kinds of plants.
Objective: To begin to explore and ask questions about grasses and grains.
Give each child a grass stem with flower/seed head, and ask what children notice and wonder about their plant.
Materials: grass stems, one per child; magnifying lenses.
GRASSES UP CLOSE
Objective: To make observations about the structure of grasses and consider how these function for the plant.
Working in small groups, give each team a complete grass plant with roots, stems, leaves, and flower head. Ask each group to share one observation about their grass plant. Other groups compare to see if their grass plant has the same or similar feature(s).
Now, using the Parts of a Grass Plant diagram as a guide, help children to consider how the different features function for the grass.
Stems: Have children describe the stems. (Thin, round in cross-section, joints where leaves attach.) Cut a stem crosswise at a node (joint) and between two nodes. Is it solid or hollow? (Hollow between nodes, solid at the nodes.) What do stems do? (Hold up the leaves, flowers and seeds, carry water and nutrients to and from the leaves.) Why might solid nodes be helpful? (Give stiffness and strength.)
Roots: Have children describe the roots. (Tangled, branching, fine, threadlike.) What function might these have for the plant? (Getting water and nutrients; anchoring the plant.)
Stolons and Rhizomes: (If these are present, hold them out from the plant so children can see them.) Are they smooth or do they have nodes? (Nodes.) Are they like the roots or like the stems? (More like stems.) How might they function for the plant? (Start new daughter plants and reach places where there might be more soil, water, nutrients or sun.)
Leaves: Have children describe the shape of the leaves, where they attach to the stem, where they bend outwards, their veins. (Thin and long, attached to stem at nodes, form a sheath around stem before extending outwards as a blade; parallel veins without a mid-vein.) What function might leaves have for the grass plant? (Catch sunlight and make food for the plant.)
Flower or seed head: Have children describe the flower or seed head’s shape, color and where it is located on the plant. (Clusters of tiny flowers/seeds at top of stem, usually in muted colors or shades of green.) What function do flowers have? (Produce pollen, form seeds.)
For older children, pass around examples of similar plants with narrow leaves that are not grasses. These could include sedges (most have triangular stems), rushes, cattails, irises or lilies (all have round stems without joints). To remember these differences, have children learn the rhyme: “Sedges have edges, rushes are round, grasses have joints from their tops to the ground.”
Give each small group a few grasses and grass-like plants. Have them sort them into those that are grasses and those that aren’t and explain their reasoning.
Materials: Parts of a Grass Plant diagram; magnifying lenses; grass plants complete with roots (dirt removed), stem, flower head, leaves – one per small group of children; for older children: a few similar non-grass plants such as sedges, cattails, irises, lilies.
PUPPET SHOW “Stalking the Wild Grasses”
Objective: To learn about some special characteristics of grasses and meet some different kinds.
Perform the puppet show, or have a group of children perform it for the class. Afterward, ask questions to review the key details and vocabulary in the story. How are grass stems different from other plants? (Jointed – have nodes.) Do grasses have flowers? (Yes!) Why are grass flowers less colorful than other flowers? (Wind-pollinated, don’t need to attract insects.) What’s different about the three grasses in the puppet show – foxtail, panic and crabgrass? (Their flowers and seed heads are different.)
Materials: puppets, script, props, stage.
PAIRING UP GRASSES
Objective: To use observations of grass plants to notice patterns of similarities and differences among them.
Ahead of time, collect samples of five to seven grasses that grow nearby, including the stem, leaves and seed heads, and make photocopies of them on letter- or legal-size paper. Give each small group of children a complete set of the photocopies. Have them spread the copies out on a table, looking for differences among them. Then hand each group a set of grasses to pair with the photocopies. Give each child a turn to match up a grass with its picture. For older children, make it more difficult by including an extra grass not represented among the photocopies.
Alternative: Spread grasses out on tables and desks around the room. Give a photocopy of a grass to each student. Ask each child to find the grass that is in their picture and then find all the other students with that grass. Now, in each group, have children figure out how to explain to their classmates how they could tell their grass from the others. If they could give their grass species a name that would fit it, what would it be? List the new names of the grasses on the board, along with their common names if anyone knows them.
Why might many kinds of grasses hold their flowers and seeds up on tall stems? (For wind pollination, scattering of seeds.)
Materials: for each small group, a set of grass stems with flower/seed heads* and set of matching photocopies; magnifying lenses, one per child. Keep the dried grasses in a large manila envelope or flat plastic bag, or in bags in a bucket.
* Grasses will dry out and get brittle and will need to be replaced if the seed heads break off.
Objective: To observe grasses outside, looking for evidence about where they grow and why.
Take the children outside and work in small teams to complete the tasks on the Grass Safari Card.
Afterward, gather the children together and talk about their findings.
In small groups:
- Take a walk around the schoolyard and see if you can find a whole plant that is a grass. Use this checklist to decide if your plant is a grass or not:
- Jointed stem with a hard node at each joint
- Stem rounded, no edges (you can roll it between your fingers)
- Leaves long and thin, pointed at the tip
- Leaf starts at a node and wraps around the stem, then bends outward
- Leaf veins parallel, like ridges running lengthwise in the leaf
- Flower head at top of stem (usually not on side branches) if present
- Flower (if present) does not have big colorful petals
Is your plant a grass? If not, keep looking until you find one.
- Close your eyes and feel your grass stem with your hands. Count the nodes. Now open your eyes and count again. Did you find them all with your eyes closed?
- Find a plant that looks like a grass but isn’t. Why do you think it isn’t a grass? (Use the checklist above!)
- Look at a grass plant in a place that has been mowed. Can you find all the features in the checklist? Can you find any that are flowering? Can a grass make seeds even if it is mowed?
- Find a grass growing in a difficult place. Why is this place challenging? Think of some reasons why a grass could grow here but another plant could not. Mark the place to show other groups.
- Find a natural place where lots of grasses are growing. Is it sunny or shady? Find a natural place where there are very few grasses growing. Is it sunny or shady? Based on this, what conditions do you think are best for grasses?
- Look for grass flowers and seed heads. How many different kinds can you find? Make a list, giving each kind a made-up name to remember it by. Collect some of each kind (ONLY IF it is plentiful) for using later in the grass displays. Which kind was the most common?
Materials: Grass Safari card, one per small group; journals or clipboards, pencils, magnifying lenses.
SUM OF THE PARTS: Journal Activity or Model Building
Objective: To review the structure of grasses by drawing or making a model of a grass plant.
Have children draw a whole grass stalk including leaves, stem, and seed head, labeling the parts and giving it a name of their choosing.
Or, with older children working in small groups, have each team make a model of a grass with paper, tape, and scissors. Explain that each team must create a grass with all its parts and give it a name of their choosing. In small groups, have the children introduce their grasses, showing their drawings or models to the others.
Materials: journals or clipboards and paper; pencils, colored pencils; paper, clear tape, scissors.
Objective: To make a woven display of the different grasses found on the school grounds.
Ahead of time, construct triangular or rectangular frames of wood or flexible branches, using yarn for the warp of the loom. Provide a frame that is about 1’x 2’ for each small group. Collect or have the children collect some grass stems and leaves. Show children how to weave their grass blades and stems into the warp. Be sure to include different seed heads from grasses on the school grounds. How many different kinds did they find?
Materials: grass stems and leaves; sticks and yarn to make weaving frames.
UPPER GRADES CHALLENGE: Schoolyard Grasses Botanical Collection (Grades 5-6)
Objective: To create a botanical collection of different grass species on the school grounds.
Ask students how we might find out what different kinds of grasses are growing on the school grounds. Show them the Sample Herbarium Grass Specimen card and discuss how a collection is helpful for identifying grass species in an area. Have students work in small groups with an adult leader, looking for different kinds of grasses by comparing the flower heads, leaves, stems, and other features. Have each student choose and pick a grass plant for making a herbarium card. The sample should include a single stem with its complete flower head. Have the students lay out their grass on an 8.5×11” sheet of white cardstock, folding the stem if needed to fit on the page, and tape it down with one or two small strips of tape. Have students complete a Herbarium Label using a field guide to identify the grass (if available), or they may just fill in the grass family – Poaceae) and glue it in the bottom right corner of the sheet.* Now gather the students together and lay the grass cards out for all to view. Sort like with like. How many different species of grasses did they find on the school grounds? Could there be others? Encourage the students to notice other grasses in the schoolyard to add to their class botanical collection.
*To press the herbarium cards, put them between several thicknesses of newsprint or scrap paper and place under a stack of books until they are dry.
Materials: Sample Herbarium Grass Specimen card; scissors for clipping grass stalks, field guide to grasses, 8.5×11”white cardstock, clear tape, pencils, Herbarium Label Template, newsprint or scrap paper, books for pressing grasses.
FOOD FOR THOUGHT
Objective: To discover how grains form an important part of our diet.
Ask children to name the foods they had for breakfast, lunch, or snack. On a whiteboard or large poster, make two lists, one for foods that come from grains and one for non-grain foods. Which list is longer? How much of our normal diet comes from grains?
Optional: For older children, provide photocopies of cereal box ingredient lists. Which of the ingredients come from grasses and grains?
Materials: white board or large poster paper, markers.
A STEP BEYOND
Wheat Sprouts Sprout wheat berries in jars with water and watch them grow over time.
Grass Art Practice the art of Sumi-e painting of bamboo in conjunction with this unit. Or make
reed pens from marsh reed stems for drawing, a technique used by the famous artist Vincent Van Gogh.
Grass Skits Have older students pantomime grass uses like a broom, grass skirt, bamboo flute, popcorn, etc.
Grains Galore Bring in a variety of different grains, such as rice, wheat, oats, millet, corn, rye, and barley, for the children to see and compare. (*Note: Buckwheat and quinoa are not grasses.)