Lesson CXXIX

The Hedge Bindweed

Leading thought—There are some plants which have such weak stems that they are obliged to cling to objects for support. The bindweed is one of these, and the way that it takes hold of objects and grows upon them is an interesting story.

Method—It is better to study this plant where it grows; but if this is not practical, the vine with its support should be brought into the schoolroom, the two being carefully kept in their natural relative positions. Several of the questions should be given to the pupils for their personal observation upon this vine in the field. It is an excellent study for pencil or water-color drawing.

Observations—1. How does the bindweed get support, so that its leaves and its flowers may spread out in the sunshine? Why does its own stem not support it? What would happen to a plant with such a weak stem, if it did not twine upon other objects?

2. How does it climb upon other plants? Does its stem always wind or twist in the same direction? How does it first catch hold of the other plant? If the supporting object is firm, does it wind as often for a given space as when it has a frail support? Can you see the reason for this?

3. Look at the leaves. Sketch one, to be sure that you see its beautiful form and veins. Note if the leaves are arranged alternately on the stem, and then observe how and why they seem to come from one side of the stem. Why do they do this?

4. What is there peculiar about the flower bud? Look at its stem carefully and describe it. Cut it across and look at the end with a lens and describe it. Turn back two sepal-like bracts at the base of the flower or bud. Are they a part of the flower, or are they below it? Find the true sepals. How many are there? Are they all the same size?

5. Examine the flower in blossom. What is its shape? Describe its colors. Look down into it. How many stamens are there, and how are they set in the flower? How does the pistil look when the flower first opens? Later? Can you see the color of the pollen? Can you find where the nectar is borne? How many nectar-wells are there?

6. What insects do you find visiting bindweed flowers? Do the flowers remain open at night or on dark days?

7. Study the seed-capsule. How is it protected on the outside? What next enfolds it? Can you see now the uses of the sepals of several sizes? Cut a seed-capsule across with all its coverings, and see how it is protected. How many seeds are there in the capsule?

8. Has the bindweed other methods of spreading than by seeds? Look at the roots and tell what you observe about them.

9. Make a study of the plant on which the bindweed is climbing, and tell what has happened to it.

10. Compare the bindweed with the morning-glory, and notice the differences and resemblances.

Supplementary reading: “Morning-Glory Stories,” in Flowers and Their Friends, Morley; Botany Reader, Newell, Chap. 10; Golden Numbers, page 74.