Flower Parts: Dissecting the Flower

Angiosperms are flowering plants. The seeds of these plants are produced within the flower, the reproductive structure of the plant. Many flowers contain colorful structures called petals. Within the petals is a central female structure, the pistil, which is made up of an ovary at the base, a stalk-like style, and a swollen top called the stigma. Surrounding the pistil are multiple male structures called stamens. Each stamen is made up of a long stalk called a filament that is topped with a button-like structure called an anther. The stamen produces pollen that fertilizes the ovule in the ovary of the pistil. In this activity you will examine a flower and identify its parts, as shown in Figure 9.1.

Materials

Flower

Tweezers

Paper towel

Activity

1. Find the petals of your flower. Note the number of petals. You may remove the petals if you cannot see inside the flower.
2. Locate the pistil in the center of the flower and note its appearance and shape. Examine the pistil to see if you can distinguish between the ovary, style, and stigma.
3. Locate a stamen of the flower and note its appearance. How many stamens do you see? Can you see any pollen on top of the stamens?
4. Examine the stamen more closely to see if you can locate the anther and filament.

Follow-Up Questions

1. Describe the appearance of the stamen and the pistil.
2. Compare the number of stamens and pistil(s) in the flower. Can you think of a reason for the difference in numbers of each?
3. Suggest some ways that pollen might be transferred from the stamen to the pistil.

Answers

1. Answers will vary depending on the types of flowers used.
2. Answers will vary, but there will be only one pistil and multiple stamens. The ovule, which will later become the seed, needs to become fertilized. Multiple stamens increase the possibility of fertilization.
3. Wind, water, insects.

Extension

Obtain other flowers and compare the number of pistils and stamens in different species. Does the number of stamens vary from one type of flower to the next? Does the number of pistils vary from one type of flower to the next? Do all flowers have both stamens and pistils?