ELECTRON MICROSCOPY: NON-HUMAN: FUN STUFF. PHYSOSTEGIA STOMATA AND SPINE OF LEAF.; SCANNING ELECTRON MICROGRAPH. PHYSOSTEGIA STOMATA. THIS IMAGE IS FROM THE SMALL BIT OF LEAF THAT SURROUNDS THE BASE OF THE FLOWER OF THE "OBEDIENT PLANT" OR PHYSOSTEGIA. ONE STOMA IS OPEN AND THE OTHER CLOSED.