Responses of plant stomata to elevated CO2 and temperature: observations from 10 plant species grown in temperature and CO2 gradients Stomatal distribution on the flower of Plumeria rubra Characteristics and dynamic changes of stomata on the hypocotyl of Brassica chinensis var.parachinensis Leaf Stomatic Characteristics of Dicotyledonous Plants in the Tibetan Plateau Grasslands Dynamic Change of Stomatal Density and Stomatal Index on the Flower during Canna generalis Bailey Development Dynamic changes of stomatal density and stomatal index during the leaf development in Catharanthus roseus Impacting factors and relationship between stomatal parameters and atmospheric CO2 concentration