The leaves floating or sticking out over water usually have a strong transpiration, though are located in a layer of air which directly borders on water and has the increased humidity. Ustyitsa are widely open and are closed completely only at night.
Owing to all these restrictions intensity of photosynthesis of succulents is small, growth and accumulation of weight go very slowly owing to what they do not differ in high biological efficiency and do not form close vegetable communities.
In water except a lack of light of a plant can experience also other difficulty essential to photosynthesis, - the shortcoming available WITH Carbonic acid comes to water as a result of dissolution of CO2 containing in air, breath of water organisms, decomposition of fossils and release from carbonates. At intensive photosynthesis of plants there is a strengthened consumption of CO2 in this connection easily there is its deficiency.