Guttation
My latest discovery of the season. Self regulating trees. Many times I passed next to them and until now I noticed the process called guttation. Salix alba white willow or schietwilg. Guttation is the exudation of drops of internal liquid out of the tips or edges of leaves of some vascular plants, and also a number of fungi. Ancient Latin gutta means "a drop of fluid", whence modern botany formed the word guttation to designate that a plant exudes drops of fluid onto the outer surface of the plant, when the source of the fluid is inside the plant. Guttation happens in a variety of plant species. At night, transpiration usually does not occur, because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude through special leaf ti...