This is a picture I took of a cross-section of one of my orchid's roots. It's been stained with Toluidine Blue pH 4.4 which is why you can see the lignified cells (blue) and the pink cells (suberin) which turn pink and blue when the stain is added. This picture is showing the cortex which is the center of the root.
Maybe you don't consider this art, but It takes a good amount of effort to get a thin enough section, the stain, the microscope, and the camera to take the photo and the end result is a very colourful and interesting photo. I have many more photos of other plants I have, but I won't include any of them in the art portal, I'll just leave them on my page to showcase them :)