Hormones are not just an excuse for irrational, teenage behavior. Hormones are crucial chemical signals generated by cells to communicate with each other inside of a multicellular organism. In animals, hormones are made by specialized glands, like the pituitary, or adrenal glands. They do things like trigger puberty, increase or decrease your heart rate, regulate appetite, growth, sleep and many other things. Plants don’t have glands and instead make hormones throughout the entire plant, usually in meristematic tissue, like the cambium, buds or root tips. Plants don’t have blood streams (note: if your plant is bleeding you should seek immediate assistance) so they rely on diffusing their hormones with the same systems they use to distribute water and sugar, xylem and phloem. But what are these hormones and what do they do? Turns out there are a lot of them and they do everything. We’ll keep it simple for you though and stick to the most important of the hormones.