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Adding Value To The Business of Cropping

Secret flowers

Learning Intentions:

    Students will be able to:
  • locate and identify the flowers of grasses, including cereals and corn or maize
  • collect and study their anthers, stigmas and pollen
  • explain the importance of wind pollination, especially with regard to cereal crops.

What You Will Need:

  • Magnifying glasses.
  • Sellotape.
  • Optional: microscopes.

Corn plant parts

Corn plant showing anthers on the tassel, and the silks which are the stigmas.




Introduction

Many important plants have flowers that we don't really notice or recognise as flowers. Yet, these flowers are very important, because they belong to plants that produce our food (for example wheat, barley, and corn) and feed our sheep, cattle and deer (for example ryegrass in pastures). In this activity you are going on a hunt to find these secret flowers.

What do do

  1. Search for plants belonging to the grass family. Spot ones that are beginning to 'go to seed' with at least one tall flower head that is still green and producing pollen. The whole flower head is called an inflorescence. Below is an inflorescence that is at the right stage. 

    Flowering grass head with anthers releasing pollen. 


  2. Collect seed heads that have small, yellow, fluffy, dangling things hanging out of them. These are the anthers and stigmas.


    Grass flower head showing an anther (large circle) and stigma (small circle). 


  3. See how observant you are by finding as many different grasses with anthers and stigmas as you can. Corn and maize are a little different. Their anthers are at the top of the plant, while the stigmas, called silks, are the stringy threads hanging out of each corn cob. (See diagram to right.)
  4. Collect samples for further study and discussion in class.
  5. In class, try collecting some of the flower parts and pollen by using sellotape or tweezers and display them for others to see. View using a magnifying glass or stereo microscope.

    Grass flower's anthers on sellotape.


  6. Draw line diagrams of the seed heads showing the anthers and stigmas. Label.

Questions and discussion

  1. Why do wind pollinated plants such as grasses and cereals not have colourful, scented flowers?
  2. Why do you think the anthers of wind pollinated flowers dangle so loosely outside the flower?
  3. If a farmer had a long narrow row of corn and a period of still weather, how might their crop be affected? Why? The photo below might help.

    Corn-cobs that have been poorly pollinated.

Hints and tips

  • Where to locate suitable grasses: At school or home look for uncut grass plants along the edges of lawns and gardens, or the corn plants in a vegetable plot. On a farm look for wheat, barley, oats or maize plants grown as crops, or, the grasses in pastures. You will also find various grasses along road verges and in wild areas.
  • Cereals such as wheat, oats, rice and corn are domesticated grasses.

Related resources

Collecting pollen Activity

Flower facts Info sheet

Flower dissection Activity

Moving pollen flower-to-flower Info sheet

Picture credits: Flowering grass head (PxHere CC0). Corn plant (LadyofHats CC0). All others Peter E Smith, NSIL.