Handbook of Nature-Study · Lesson CLXXIII · Topic 26: Ferns, horsetails and mosses
173. The Christmas fern
Goal: Your child learns the names of the parts of a fern, finds the fruit-dots under the narrow tip leaflets, and explains why it is called the Christmas fern.
You'll need
- Nature notebook, pencil and colored pencils
- A hand lens (magnifying glass)
- A hand-drawn chart of fern part names (frond, blade, stipe, rachis, pinna, sorus)
What's in the book
The start of “Flowerless-Plant Study,” with an introduction to ferns, a Teacher's Story about the Christmas fern and the lesson: Leading thought, a Method that teaches the fern words, a labeled leaf-print of a fern, and six questions.
The lesson, step by step
When and where
Comstock says late May, when the fruit-dots are still green, and again in July. The Christmas fern stays green all winter, so you can find it any time in shady woods, especially on slopes that don't face south.
Before you go, make sure your child can spot poison ivy: three leaflets on each leaf ("leaves of three, let it be"), often climbing as a hairy vine or growing as a low patch.
The leading thought
The fern has a creeping underground stem called the rootstock, which pushes forward and sends up fresh fronds each year. Some of the fronds of the Christmas fern bear spores on the lower surface of the terminal pinnae.
Fern words
Comstock wants these words used often. Read a few and point to each part on a real fern:
A frond is all of the fern which grows on one stem from the rootstock;
the pinna is a chief division of the midrib or rachis, when the fern is compound;
the sori are the fruit dots;
Compare with the labeled leaf-print in the book.
The clump
Are there any withered fronds? Where do they join the rootstock? Do the green fronds come from the same place on the rootstock as the withered ones?
Comstock says to dig up a fern for school. Please leave wild ferns in place; study the clump where it grows.
The pinnae
Take a lower pinna and draw it carefully, showing its shape, its edges and its veins. Is there a point, or ear, at the base of every pinna?
Fruit-dots
Take one of the narrow pinnae near the tip of the frond, and examine it beneath. Can you see some circular, roundish blisterlike dots?
Do all the fronds of a fern clump have these narrowed spore-bearing pinnae?
Turn a frond over without picking it and use the lens.
Nature notebook
Where do you find the Christmas fern growing? Do you ever find it in a sunny place? Why is it called the Christmas fern?
Draw one pinna with its little ear, and the tip of a fertile frond from above. Label with the fern words.
Tip
After a walk through woods or tall plants, check everyone for ticks.
Answers to the book's problems
It stays green all winter and was much used for Christmas decoration. Comstock says it loves shade, is rarely found on slopes facing south, and that sunshine kills it. Each pinna has a small ear-like point at its base.
Worked out for this site from the scan. If a number in your copy differs, trust the book.