Lesson CXLV

The Jewelweed, or Touch-me-not

Leading thought—The jewelweed may be found by the brookside, in swamps, or in any damp and well-shaded area. It is provided with a remarkable contrivance for scattering its seeds far afield. It has no liking for open sunny places, unless very damp. There are two kinds, often found growing together, though the spotted touch-me-not (Impatiens biflora) is said to be more widely distributed than its relative—the golden, or pale, touch-me-not (Impatiens aurea).

Method—The jewelweeds should be studied where they are growing; but if this is impracticable, a large bouquet of both kinds (if possible), bearing buds, blossoms, and seed-capsules, and one or two plants with roots, may be brought to the schoolroom.

In the fields the children may see how well the plant is provided with means to sustain itself in its chosen ground, and thus lead them to look with keener eyes at other common weeds.

Observations—1. Do you think the jewelweed is an annual, sustaining life in its seeds during winter, or do its roots survive?

2. Do the roots strike deeply into the soil, or spread near the surface?

3. Study the stem; is it hard and woody or juicy and translucent, rough or smooth, solid or hollow?

4. Note the shape and position of the leaves; do they grow opposite or alternately on the stalk? Are their edges entire, toothed or scalloped? Do they vary in color on upper and lower surface? Are they smooth or in the least degree rough or hairy? Plunge a plant under clear water in a good light and observe the beautiful transformation. Does the water cling to the leaves?

5. Where do the flower-stems spring from the main stalk? Do the flowers grow singly or in clusters? Do the blossoms all open at nearly the same time or form a succession of bud, flower and seed on the same stem?

6. Study the parts of the flower. Find the four sepals and describe the shape and position of each. Describe the nectar-sac in the nectar-horn. Can you find the two petals? Can you see that each petal has a lobe near where it joins the stem? Find the little knob hanging down above the entrance of the nectar-sac; of what is it composed? Look at it with a lens, and tell how many stamens unite to make the knob? Where is the pollen and what is its color? What insect do you think could reach the nectar at the bottom of the spurred sac? Could any insect get at the nectar without rubbing its back against the flat surface of the pollen boxes? What remains after the stamens fall off? Describe how the bees do the work of pollenation of the jewelweeds. Write or tell as a story your own observations on the actions of the different bees visiting these flowers.

7. Carefully observe a seed-capsule without touching it; can you see the lines of separation between its sections? How many are there? What happens when the pod is touched? Are the loosened sections attached at the stem, or at the apex of the pod? Hold a pod at arm’s length when discharging its contents and measure the distance to which the seeds are thrown. Of what use is this habit of seed-throwing to the plant?

8. Describe the differences in shape and color between the pale yellow and the orange jewelweeds. Watch to see if the same insects visit both. Which species do you think is best suited to the bumblebees?