Stomata
/STOH-mah-tah/🔬 Anatomy●● Intermediate
Also known as: stoma, stomates
Stomata (singular: stoma) are tiny openings in the leaf epidermis, each flanked by two guard cells that regulate the pore's opening and closing. Open stomata allow carbon dioxide in for photosynthesis and release oxygen and water vapor (transpiration). Guard cells close stomata during drought or at night to conserve water. Most dicots have stomata primarily on the lower leaf surface; grasses have them on both surfaces.
Etymology
From Greek stoma (mouth)
Example
“During the afternoon heat, the guard cells closed the stomata to prevent excessive water loss through transpiration.”