You can see a pair of guard cells, a stoma between them, and cuticular hairs partically covering the stoma. The covering of cuticular hairs helps maintain high relative humidity near the stomatal opening and reduce rapid water loss through the stoma. Monocot leaf epidermis x40. You can see pairs of guard cells and other cells of this upper epidermis. Dark dots are nuclei.
Rectangular cells are over a leaf vein.
Stomata are between veins. Tradescantia upper leaf epidermis x100. Note the lack of stomata on this leaf surface. The black dots are nuclei. Unlike this species, many dicot plants have a few stomata on their upper surface.