Willow up close
David photographed the crystallised chemical salicin, which comes from willow tree bark. Salicin forms the basis of the analgesic Aspirin – no doubt this is why some animals seek out willow bark to chew on.
Canon EOS 5D Mark II; 50x magnification on full frame sensor; Olympus BX51 microscope; 1/4 sec at 5x UPlanFL; ISO 50; Polarisation Microscopy.
Vote for this image
Voting closes at 14:00 on Tuesday 4 February 2020.