The stomates are interspersed in the lower epidermis of the leaf.
The nuclei are stained red, Chloroplasts are visible in the guard cells.” alt=”Epidermis of a Tulip showing Stomates
Stomates (or stomas) are openings on the underside of a leaf, which allow gases to pass in and out of the leaf. The pictures show these stomates as narrow gaps. Two guard cells control the size of the opening. The guard cells have chloroplasts, which are visible as dark dots in the cell. During the day the stomates open to allow carbon dioxide gas to enter the leaf. During night the stomates close to minimize the loss of water vapor from the leaf.
Further reading
April 13th, 2011 at 04:53
You’ve probably already done this, but I’ve always enjoyed this experiment: since the guard cells rely on the concentration of potassium ions to open or close, one can manipulate the stomata to open or close by soaking the leaf in a salt water solution or a distilled water solution. I forget which solution opens or closes the guard cell, but it’s certainly an interesting experiment!