FLOWER DISSECTION

Mounting a flower allows you to see how a plant reproduces sexually.



A complete flower (we recommend gladiolas or fuchsias because they are easy to find and one stem contains several flowers, which makes them inexpensive for classroom use).

An old manila file folder

Unlined white paper

Clear magic tape

Sharp scissors

Small white stick-on labels

Colored pencils or fine tip markers

Glue stick




Prepare your mounting board first. Take a manila file folder and cut it open. One side is sufficient for a mounting board. Cut a sheet of white paper so that half of it will form a rectangle that will cover the bottom half of your mounting board. Glue this on. Cut a smaller rectangle from the white paper and glue that onto the top right-hand corner of your board. The larger lower rectangle will be used to lay out and tape down the parts of the flower once they are cut. The smaller rectangle will be used to draw and color a diagram of the dissected flower.

Now you are ready to dissect the flower. Find the hard base of the flower, the receptacle, and cut below it. Peel off the green leafy sepals that protect the receptacle and put them aside. Also peel away some of the petals and put them aside. Make one sharp transverse cut across the sepal, which will expose the ovary and the very tiny eggs within. Notice the pistil (female reproductive part) is one slim tube extending up from the ovary. The several stamens (male reproductive parts) are tubes attached to the outside covering of the receptacle.

Lay out your cut-open flower with the two parts of the ovary towards the bottom of your mounting surface letting the pistil extend upwards. Lay a sepal next to the ovary. Now arrange a couple of stamens on each side of the pistil and lay out a few petals next to the stamens. Use a lot of magic tape to flatten down your entire flower parts. In a week or two, the dissected flower will dry out, and it will be functional as a permanent display for many years. Use the stick-on labels to write each plant part and put these labels at the appropriate places on your display. You need ten labels in total: receptacle, ovary, sepal, petal, stamen - anther, filament, pistil - stigma, style.

Illustration from THE WORLD BOOK ENCYCLOPEDIA, 1995 edition

Use colored pencils to draw out what you have dissected and label it completely on the smaller white rectangle that you have glued to the upper right-hand corner of your mounting board.




The stamen produces pollen, "plant sperm," which sits on the anther, the tiny platform on top of the filament. Pollinators are attracted to the flower by its colorful petals. A pollinator like an insect or the wind takes pollen from the anther to the sticky stigma on top of the style. Microscopic male sex cells descend down the style to the ovary where the eggs are fertilized. A fertilized flower becomes a fruit. When this fruit is ripe, it will have the seeds necessary to produce offsprings.

Illustration from the 1989 textbook LIFE SCIENCE MACMILLAN

 

By
Erainya Neirro

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