Lesson CXXXVII

The Asters

Leading thought—There are very many different kinds of asters, and they all have their flowers arranged similarly to those of the sunflower.

Method—Have the pupils collect as many kinds of asters as possible, being careful to get the basal leaves and to take notes on where each kind was found—that is, whether in the woodlands, by the brooksides or in the open fields. This lesson should follow that on the sunflower.

Observations—1. What was the character of the soil and surroundings where this aster grew? Were there large numbers of this kind growing together? Were the flowers wide open when you gathered them? How soon did they close?

2. How high did the plants stand when growing? Were there many flowers, or few, on each plant?

3. Study the lower and the upper leaves. Describe each as follows: the shape, the size, the edges, the way it was joined to the stem.

4. Is the stem many-branched or few? Do the branches bearing flowers extend in all directions? Are the stems hairy or smooth, and what is their color?

5. What is the diameter of the single flower-head? What is the color of the ray-flowers? How many ray or banner-flowers are there? What is the shape of a single banner as compared with that of a sunflower? What are the colors of the disk-flowers? Of the pollen? Do the disk-flowers change color after blossoming?

6. Look at the bracts below the flower-head. Are they all the same shape? What is their color? Do they have recurved tips or do they overlap closely? Are they sticky?

7. Take the aster flower-head apart and look at it with a lens. In a disk-flower, note the young seed, the pappus, the tubular five-parted corolla, the anther tube and the stigmas. In the ray-flower, find the young seed, the pappus and the stigma.

8. Watch the bees working on asters, and find where they thrust their tongues to reach the nectar.

9. Study an aster plant in November, and describe the seeds and how they are scattered.