In hydrology, evaporation and transpiration (which involves evaporation within plant stomata) are collectively termed evapotranspiration. Unlike most epidermal cells, the guard cells of plant stomata contain relatively well-developed chloroplasts. They help to regulate the rate of transpiration by opening and closing the stomata. These pores superficially resemble the stomata of other plants. Structures that help plants prevent disease are&colon; cuticular layer, cell walls and stomata guard cells. Epidermis is single layered usually with obvious stomata. In anatomy, a stoma (plural stomata or stomas) is any opening in the body. Transpiration refers to the expiration of water through the minute pores or stomata of trees. The conidia infect the plant by entering through small wounds, stomata, or direct penetration. This work included the discovery and naming of parenchyma and stomata. The plants may recover during the night when evaporation is reduced as the stomata closes. They have rather large compound leaves without glands and stipules, and with anomocytic stomata. The bacteria infect new plants through stomata and wounds. Bacteria frequently infect plants by gaining entry to the tissue via the stomata. In vascular plants the number, size and distribution of stomata varies widely.