This is a (pretty low quality) image of a pollen sample from the pink flowers next to Linde on Caltech’s campus. The sample was obtained at 4pm on 5/8/19. The sample was obtained by scraping the insides of the flower to get the dusty stuff (aka pollen). The dark spots in the image are the pollen.
The foldscope has 140x magnification, and each pollen grain is about 1mm across. Therefore, each pollen grain is ~7 micrometers in diameter.