Indeed, each pollen grain has a clearly defined and species-specific shape and size that are not visible to the naked eye, since a pollen grain measures between 2.5 and 220 microns (thousandths of a millimetre). The shape is often spherical, ovoid or triangular, more or less deformed but always harmonious. Palynology (from the Greek palyno = to spread, to scatter – itself derived from pale = flour – and logos = science, discourse) is a science devoted to the search for pollen grains and the study of their morphology (external form). Research and analyses have made it possible to create a kind of database in which several hundred pollen species are catalogued, with descriptions and drawings or microscopic photographs, which can be compared with those found in honey.

The beekeeper may see little interest in distinguishing the shapes of different pollen grains, but will be much more interested in knowing the nature of their honey. Honey contains, in addition to wind-transported pollen, traces of pollen from the flowers visited by bees: a certain number of small pollen grains are naturally diluted in the nectar collected by the bee; larger pollen grains remain attached to the insect’s body surfaces and may fall into the honey stored in the wax combs.

The study of these pollen grains (pollen analysis and melissopalynology, which examines pollen present in honey) makes it possible to determine the geographical origin and the botanical origin of honey.

 

 

Geographical origin

Since honey contains traces of pollen from all plant species in the region, whether transported by bees or by wind, pollen analysis provides an indication of the origin of the honey (for example mountain honey or imported honey). This makes it possible to determine, for instance, whether a honey sold as local was actually harvested in Switzerland (it must not contain pollen from exotic plants).

 

Botanical origin

Pollen analysis of honey also (and above all) aims to identify which plants supplied the nectar used to produce that honey and in what proportions. There is in fact a proportional relationship between the number of pollen grains from a given plant species present in honey and the amount of honey derived from that plant (notable exceptions include chestnut, whose pollen is over-represented, and dandelion, which is under-represented).

With regard to honeydew, since bees do not forage on pollen-bearing flowers, the usual rules of pollen-based identification cannot be applied. Only an indication of the plants present in the region (geographical origin) can be provided, as pollen particles from these plants settle on the honeydew before it is collected by the bees.

 

Sources

Silberfeld, C. Reeb, Les plantes mellifères, 2016

Jean-Prost, Apiculture, 1987

Agroscope, Important sources of pollen and nectar for honey bees in Switzerland, 2020

Piquée, Les plantes mellifères mois par mois, 2014

Bieri, S. Bogdanov, Beekeeping – a fascination, Vol.4 Hive products, 2014

Swiss Beekeeping Review SAR, March 2018

Caillas, Le pollen

Donadieu, Le pollen, 1979

Hakim, Le pollen