Handbook of Nature-Study · Lesson CXXV · Topic 19: Spring wildflowers of the woods
125. The bluets
Goal: Your child uses a hand lens to find the two forms of bluet flowers and works out how insects carry pollen between them.
You'll need
- Nature notebook, pencil and colored pencils
- A hand lens (magnifying glass)
- A small sharp pin or toothpick (adult helps)
What's in the book
A Teacher's Story about bluets, with a photograph and a poem about bluets, and the lesson: Leading thought, Method and seven questions.
The lesson, step by step
When and where
Bluets bloom in spring, often from April to June, in masses on damp meadows, lawns and grassy banks. They are tiny: four pale blue petals around a yellow eye.
The leading thought
The bluets have two forms of flowers, the anthers and stigmas being placed in different positions in the two, in order to secure cross-pollenation by visiting insects.
Where do they grow?
Where do the bluets grow? Do they grow singly or in masses? On what kind of soil do they grow, in woods or meadows? At what time of year do they bloom?
Describe one flower
Describe the bluet flower, its color, the shape of its sepals, the form of the corolla, the color of the corolla-tube and lobes.
Where is the nectar in the bluet? What color shows where the nectar is to be found?
The two forms
Lie down on the grass with the lens and look straight into many flowers.
Look directly into the flowers. Do you see any with the stigmas thrust out of the corolla-tube?
Look for a flower where the stigmas do not protrude and the anthers close the throat of the tube.
If bluets grow in your own lawn, pick one of each kind and (with an adult) slit the tube with a pin to see where the anthers sit.
The puzzle
Work out this problem: How do the insects gathering nectar from one form of the bluets become dusted with pollen in such a way as to leave it upon the stigma of the other form of the bluet flower?
Let your child try to explain it with two drawings side by side.
Nature notebook
Draw the two forms of flower as if cut in half: one with the stigma high and anthers low, the other the opposite. Draw a bee's tongue going in.
Afterwards
Count how many of each form you find in one patch of bluets. Are they about even?
Answers to the book's problems
In one form the stigma is high and the anthers low; in the other, the anthers are high and the stigma low. Pollen rubs onto the insect's tongue at one height and is left on a stigma at the same height in the other kind of flower.
Worked out for this site from the scan. If a number in your copy differs, trust the book.