the stomata are usually found in the in the leaf.
where are the stomata usually found on a leaf?
in the
stomata are present in the sporophyte generation of all land plant groups except liverworts. in vascular plants the number, size and distribution of stomata varies widely. dicotyledons usually have more stomata on the lower surface of the leaves than the upper surface. monocotyledons such as onion, oat and maize may have about the same number of stomata on both leaf surfaces. in plants with floating leaves, stomata may be found only on the upper epidermis and submerged leaves may lack stomata entirely. most tree species have stomata only on the lower leaf surface. leaves with stomata on both the upper and lower leaf are called amphistomatous leaves; leaves with stomata only on the lower surface are hypostomatous, and leaves with stomata only on the upper surface are epistomatous or hyperstomatous. size varies across species, with end-to-end lengths ranging from 10 to 80 µm and width ranging from a few to 50 µm.
stoma
stomata are obvious holes in the leaf by which, as was presumed for a while, pathogens can enter unchallenged. however, it has been recently shown that stomata do in fact sense the presence of some, if not all, pathogens. however, with the virulent bacteria applied to "arabidopsis" plant leaves in the experiment, the bacteria released the chemical coronatine, which forced the stomata open again within a few hours.





























section::::stomata and climate change.





























section::::stomata and climate change.:response of stomata to environmental factors.
stoma