FOR WAGGONER’S BIOLOGY 
3 
EXERCISE 3 
THE SIMPLE FLOWER 
Use the radish or mustard blossom or that of a single geranium 
for this study. Use a hand lens freely in this exercise. 
I. Where is the flower borne on the plant? Is it borne in a 
cluster or singly? What are its shape, size, and color? 
II. Structure. What differences in the flower and the bud are 
evident? The stem of the flower, the peduncle, may have an en¬ 
larged end, the receptacle, to which the circles of parts are 
attached. (In some cases one or more green structures, somewhat 
leaf-hke in form, may be attached to the peduncle near the flowers. 
These are bracts.) 
1. The outside circle of parts situated upon the receptacle is 
the calyx. Each of these parts is a sepal. Note the number, shape, 
and color of the sepals. What is the function of the calyx? 
2. Next to the calyx is a circle of parts known as the corolla. 
Each of its parts is a petal. Note the number, shape, and color of 
each. Compare with the sepals. What is the function of the 
corolla? 
3. The next circle of parts is the circle of stamens. Note the 
number, the structure, and the arrangement of these. Each 
stamen is made up of the stalk, or filament, and of the enlarged tip, 
or anther. Observe the anther closely. What does it contain? 
This yellow powder is pollen. What is its use? 
4. The central structure of the flower is the pistil. What is its 
shape? Its position? The enlarged base is the ovary, the tip is the 
stigma, and the connecting part is the style. Do you find a sub¬ 
stance adhering to the stigma? What is it? What is pollination? 
Cut off the ovary. Does it contain more than one cavity? Crush 
the ovary. What is the nature of its contents? The tiny objects 
are ovules. What is their relation to seed development? What is 
the function of the stigma? The style? The ovary? 
