Today let’s take a look at some plants that are often ignored because they lack big, showy flowers. Ferns, liverworts, horsetails and mosses do not produce seeds, but produce spores instead.
Activity 1. Identification
Go on a nature walk and see if you can spot any of these spore-producing plants. Record where you see them and what the surrounding environment is like.
Mosses are low-growing plants with tiny leaflets. They coat the ground like velvet.
Liverworts have rounded leaflets that are said to resemble the liver.
Horsetails have tall stems, with segments. Their leaves are long and fine, resembling a horse’s tail.
Did you find any of these plants?
Activity 2. Searching for spores.
Because these plants make spores instead of seeds, it is fun to see if you can find the structure that produces spores, the sporangium. If you don’t have any of these plants growing nearby, check with your local florist. They sometimes use ferns in bouquets.
See the dark dots on the underside of the frond? Those are the sporangia.
Check out this video of fern spore capsules shooting out the spores like a catapult!
The yellow brown structures on this moss are the sporangia.
What is the difference between a seed and a spore? A spore is a single cell, so it is tiny. In comparison, a seed contains many cells making up the embryo of the plant, the food that is stored with it, and a cover or coat.
Activity 3. Moss, horsetail, fern and liverwort habitats.
When you went on the nature walk, where did you find these plants? Did you find them mostly in wetter areas? Were any growing in the forest?
Did you find them growing together?
Ferns, mosses, horsetails and liverworts have somewhat similar growing requirements. Liverworts and mosses are considered to be non-vascular plants because they lack the special water-carrying tubes found in other plants. They must stay in relatively wet environments and can’t grow tall.
Aren’t these interesting plants?
Edit: If you are interested in learning more, take a look at Steve Parker’s Ferns, Mosses and Other Spore-producing Plants book, which is part of the Kingdom Classification series. I have a review at WrappedinFoil.
Did you do the tree leaf age experiment last spring to see how long tree leaves stay on the tree? Now would be a good time to check your trees. Let us know what you found out so far. Some of the leaves we marked on our orange tree last spring are still on the tree.
If you live where trees are deciduous, you might want to study the next step: what happens to leaves when they fall off the tree?
First, think about and make a list of what you think might happen. Do you think some might be eaten, or that they will all blow away?
Scientists study the decomposition, or breakdown of leaves, by putting leaves in nylon mesh bags and letting them sit on the ground for long periods of time. The researchers come back every few weeks and pick up a few bags to take back to the laboratory. They open the leaf bags up and see what is happening. They look at things like how much weight the leaves lost, what kinds of critters have been eating the leaves, and how the leaves have lost chemicals (nutrients) over time.
You can make your own leaf bags (also called litter bags).
Gather:
Heavy duty screen door nylon mesh (1 x 2 mm mesh size is best) or the nylon mesh bags that fruits or onions come in from the grocery store.
Equipment, such as scissors, for cutting screen mesh
Equipment for closing the screen bag: glue gun or sewing needle and thread (soldiering irons can be used by adults).
Place you can safely leave leaf bags under trees and be able to retrieve them over time
If you are using the pre-made nylon bags from the grocery store, you can skip this step. If you are using screen door mesh, cut out strips 10 inches (25 cm) wide and cut into 8 inches (20 cm) sections and fold in half. Use the glue gun, needle and thread or soldiering iron to seal two sides. Leave one end open so you can put the leaves in.
Once you have the leaf bags made, go outside and fill them with leaves. Try to use freshly fallen leaves and collect only the leaves from under the trees where you will be leaving your bags. If the leaves are too dry, you can wet them with a bit of water to get them into the bags without crumbling. The grocery store bags will have larger openings, so you might want to use bigger leaves.
Close the bags with hot melt glue, or by sewing or tying them shut. Place the leaf bags outside in a place where you can safely retrieve them. You might consider marking the bags with sticks in the ground or tying the bags to brightly colored tent pegs shoved into the ground.
Now you have to be patient. Check the bags roughly every month and see how they are faring. Leave them under the trees until next year and then be sure to collect them. Open the bags into a tray or pan and sort through the contents. What do you think you might find?