Here is white clover (Trifolium repens) pollen at 400x magnification near the center of the image. These pollen grains are roundish with a diameter of about 20 micrometers. Right click for full resolution.
To compensate for depth of field limitations, this image was created by focus stacking 6 images using Hugin Tools.
Equipment used: AmScope M150C microscope with Raspberry Pi camera module V2 (8MP).