Pollen identification

To identify the pollen grains under the microscope you will need to use four sources of information:

(i) Pollen Identification Photographs

The photos included here low-resolution images of pollen grains. The common name is on each image, its botantical name and size are given immediately below. High resolution images can be downloaded.

Pollen grains under the microscope have distinct structural characteristics. Points to note when identifying pollen types:

• pollen grains stain pink, and starch granules released from pollen stains dark red to black.
  
• a pollen grain has one or more holes on the surface called an aperture. The aperture releases starch granules.
  
• grass pollen is generally identified by a single aperture, round shape, and well defined pollen grain wall.
  
• tree pollen has more than one aperture, some having many apertures, and the shape of the grain can vary greatly from Family to Family.

(ii) Pollen Calendar

Pollen grains can be grouped into: Trees, Grasses, Herbs and Weeds

Refer to a Pollen Calendar for your state. This will indicate which plant types could be contributing to the airborne pollen count for that time of the year.

(iii) Your observations of the sampling location

Investigate your local trees, grasses, herbs and weeds for evidence of pollen bearing flowers (be careful not to confuse your identification with insect pollinating plant types).

Note down any obvious flowering plant types that can be identified. Collect plant samples to bring back to the laboratory. You may be able to shake pollen from the plant specimen onto a glass slide and view it under the microscope. This will help to identify pollen on your filter paper.

(iv) ACTIVITY: Making a pollen reference slide

Aim:

• To collect flower samples of wind pollinating plants in your local area
• To prepare a reference pollen slide from the local wind pollinating plants
• To identify pollen on the prepared slide.

Method:

1. Refer to the Pollen Calendar (Appendix) and determine the plants contributing to the airborne pollen in your area, eg. grasses, trees, weeds.
   
2. Collect a small branch with flowers from a wind pollinating tree, grass or weed.
   
3. Leave for ~1 hour before step 4.
   
4. Lightly smear a glass slide with vaseline.
   
5. Lightly dab the flower onto the glass slide.
   
6. Saturate the pollen on the slide with Calberla's stain, and place a coverslip over the sample.
   Observe pollen grains under the microscope.
   
7. Repeat this activity to generate reference slides of a flowering tree, grass or weed in your area.
   

Modified: 16 May 2002