Calotropis procera and C. gigantea both grow successfully in dry areas. Tezara et al. examine their ecophysiological traits and find that photosynthesis is co-limited by stomatal and non-stomatal factors under drought without chronic photoinhibition in both species. The photosynthetic capacity of C. procera is higher than that of C. gigantea, which provides an explanation for its wider and more frequent distribution; however, a higher density of trichomes in C. gigantea provides a photoprotective mechanism that improves its relative performance under drought.
