Handbook of Nature-Study · Lesson CLXXVIII · Topic 26: Ferns, horsetails and mosses
178. The hair-cap moss
Goal: Your child can find the spore capsule, its silky cap and lid, and the star-cups on hair-cap moss, and can show how dry moss changes when it gets wet.
You'll need
- A small clump of hair-cap moss with capsules on stalks (June is best)
- A glass of water
- A white paper
- A hand lens (magnifying glass)
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
The lesson compares the stages of moss to the stages of a butterfly, then gives eight observations on the stem, the leaves, the silky cap or "veil," the spore capsule, the yellow star-cups and what dry moss does in water.
The lesson, step by step
When and where
Go in June to a sunny knoll, a woods edge or an old field where hair-cap moss grows thick, like a carpet of tiny pine trees. Many stems will have a little capsule held up on a shining stalk, which the book calls "pigeon wheat."
Take only a small clump, and press the rest of the moss back down.
The leading thought
The butterfly stages are the egg, the caterpillar, the chrysalis, the butterfly. The moss stages are the egg (or ovule), the spores, the branching green threads, the moss plants with their green foliage.
Tell the book's fun facts too: Laplanders stuffed pillows with this moss and bears use it for their beds.
Stem and leaves
Take a moss stem with a grain of pigeon wheat at the end. Examine the lower part of the stalk. How are the leaves arranged on it?
Are the lower leaves the same color as the upper ones? Why?
Cap, lid and spore vase
Note the silken cap on a grain of the pigeon wheat. This is called the veil.
Take it by the tip, and pull it off. Is this done easily? Describe what it covers.
Under the cap is the spore capsule. Look at its lid with the lens. Then find an old capsule with no lid, and tap it over white paper:
See if you can shake any dust out of such a spore vase. What do you think this dust is?
The star-cups
Hunt among the moss for some stems that have pretty, yellowish, starlike cups at their tips.
Look down the stem and see if you can find last year's cup. The cup of two years ago?
Dry moss, wet moss
Let a few stems dry for a day, then look at them with the lens. Put them in a glass of water and watch for ten minutes.
Place these dried stems in a glass of water and describe what happens to the cup.
Of what use to the moss is this power of changing form when damp?
What we know now
The star-cups grow on male plants and hold sperm cells. Rain splashes them over to the female plants, where the eggs are. Each spore capsule grows from one of those eggs. Spores that land on damp ground grow into green threads, and new moss plants bud from them.
Nature notebook
Draw one moss stem with its capsule, and draw the capsule large with its veil beside it. Draw a dry leaf and a wet leaf. Write which changed and how.
Answers to the book's problems
The dust is spores. Dry leaves fold and twist close to the stem, which keeps the moss from losing water; in water they spread out again within minutes. Counting the old star-cups down a stem tells about how many years old it is.
Worked out for this site from the scan. If a number in your copy differs, trust the book.