Methods: Pollen Analysis
Pollen grains produced by different species of plant have a distinctive appearance. This allows us to work out what type of plant they came from, which in turn tells us the plants that used to grow in the area. We can observe the distinctive features of different types of pollen using a microscope. This helps us to identify what they are.
Two useful features for identifying pollen are pores and furrows. Pores are holes in the surface of a pollen grain. Furrows are slits in the surface of a pollen grain. These features are highlighted in the images above. You can hide these annotations by placing the mouse arrow over each image.
Beech and Lime pollen both have three pores and three furrows. It is possible to tell these grains apart because Beech pollen has much longer furrows than Lime. Lime pollen also has thickenings around the pores, which Beech pollen does not have.
Goosefoot pollen has many pores (at least 40) but no furrows (Moore et al., 1991). Wild grass pollen has one pore and no furrows.
Other common pollen types: Place the mouse arrow over each image to see the features of these grains. These are described below.
Pine pollen has two air sacs attached to the pollen grain, which makes it look like Mickey Mouse. These air sacs help it to be transported by the wind over great distances.
Birch pollen has three pores. These stick out from the surface of the grain. The number and shape of the pores are key to identifying this grain.
Alder pollen has anywhere between three and five pores. This example has four. The key characteristics of this grain are the shape of the pores and the presence of arc-shaped shadows between the pores.
Hazel pollen has three pores. These are much smaller than those of Birch and Alder. The number and shape of the pores are key to identifying this grain.
Ribwort plantain pollen has anywhere between eight and fourteen pores, but no more than this. Some of the pores are hidden behind the grain in this picture and are shown with a dotted line. The pores are randomly distributed over its surface. They contain a “plug” of pollen material, which makes the centre of the pores stick out slightly. We use this feature and the number of pores to identify this grain.
Cereal pollen looks very similar to grass pollen. It has one pore and no furrows, and it is a delicate grain which folds easily. It can be told apart from grass pollen because it is at least three times the size and its pore has a thickened edge. This is not seen in grass pollen.