Sap by the fact that phloem sap is physiologically extreme in terms of animal digestion, and it is hypothesized that few animals take direct advantage of this because they lack two adaptations that are necessary to enable direct use by animals. These include the existence of a very high ratio of non-essential/essential amino acids in phloem sap for which these adapted Hemiptera insects contain symbiotic microorganisms which can then provide them with essential amino acids; and also insect "tolerance of the very high sugar content and osmotic pressure of phloem sap is promoted by their possession in the gut of sucrase-transglucosidase
Plant secretory tissue the poisonous secretion is released. Glands secreting a sugary liquid—the nectar—in flowers pollinated by insects are called nectaries. Nectaries may occur on the floral stalk or on any floral organ: sepal, petal, stamen, or ovary. The hydathode structures discharge water—a phenomenon called guttation through openings in margins or tips of leaves. The water flows through the xylem to its endings in the leaf and then through the intercellular spaces of the hydathode tissue toward the openings in the epidermis. Strictly speaking, such hydathodes are not glands because they are passive with regard to the flow of water. Some carnivorous plants