Silver birch pollen grain. Coloured scanning electron micrograph (SEM) of a pollen grain from the flower of silver birch (Betula pendula). The outer wall of the grain (exine) has three pores. Silver birch pollen causes an allergic reaction in around a quarter of hay fever sufferers. Magnification: x4318 when printed at 10 centimetres wide | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / BIOMEDICAL IMAGING UNIT, SOUTHAMPTON GENERAL HOSPITAL |
Taille de l’image : | 3201 px × 2744 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |