Handbook of Nature-Study · Lesson CXXVIII · Topic 20: Summer wildflowers, climbers and water plants
128. The evening primrose
Goal: Your child watches an evening primrose flower open at dusk, times it, and explains why a pale yellow flower suits night-flying moths.
You'll need
- Nature notebook, pencil and colored pencils
- A hand lens (magnifying glass)
- A watch or phone clock
- A flashlight
- Insect repellent for an evening outing
What's in the book
A Teacher's Story with a photograph of the winter rosette, and the lesson: Leading thought, Method and nine questions.
The lesson, step by step
When and where
Evening primrose grows on dry roadsides, waste places and field edges and blooms from summer into October. Its tall, stiff stalks carry pale yellow flowers that open toward evening. A garden kind works too. This lesson needs a visit at dusk.
The leading thought
Some flowers have developed the habit of relying on the night-flying insects for carrying their pollen. The evening primrose is one of these; its flowers open in the evening and their pale yellow color makes them noticeable objects in the twilight, and even in the dark.
The whole plant (daytime)
Look at the plant as a whole. How tall is it? Is the stem stiff and straight? Where do you find it growing?
Where on the plant do the flowers grow? Which flowers blossom first, those above or below?
The opening
Go back at sunset and pick out a bud that looks ready to open. Then watch it closely.
Watch the flower of the evening primrose open, and describe the process carefully. At what hour did it open?
How many minutes is required for the whole process of the opening of the flower? How many flowers on a plant expand during the same evening?
In the dark
Look at the open blossoms in the dark; can you see them? How do they look? What insects do you find visiting these flowers?
Switch the flashlight off for a minute and let your eyes adjust. Pale flowers glow; dark ones disappear.
Next morning
How long does the primrose blossom remain open?
Comstock also asks the children to taste the flower tube for nectar. Skip that: Never taste any part of a wild plant, berry or seed.
Nature notebook
Draw the flower in three stages: tight bud, half open, fully open. Write the times beside each drawing.
Afterwards
In late fall or winter, look for the flat winter rosette of leaves at the base of old stalks (the book has a photograph).
Tip
Moths that visit at dusk include sphinx moths that hover like hummingbirds. Watch them; don't catch them.