The world of plants may seem quiet and calm. But you don't need to go much farther than your front door to find drama afoot. Like, that sweet, summery scent of freshly cut grass? It's actually the plant equivalent of a scream. Through chemicals, grass is sounding a warning call to nearby plants, which start putting up their defensive dukes, getting ready to protect themselves from damage. And plants are smart. They can tell the difference between mechanical damage, like that lawn mower, and being chomped by an insect. If bugs are attacking, plants can release special chemicals that yell to other bugs nearby, "Please come eat whatever's eating me." So your quiet, summer afternoon has just turned into a plant action movie, complete with elaborate fight sequences. We humans think we're such a big deal, but if you squished up every living thing on the planet into one big ball, eighty percent of it would be plants, and less than one percent would be mammals. Some folks say we're missing the forest for the trees, but we're also missing the trees! And the ferns, and the mosses, and the palms and the sedges. There's a whole other world here, and it's all around us. You see, plants aren't just a bunch of wallflowers. You just weren't a part of their group chat yet. But that's all about to change, and they have so much dirt to dish out. Hi! I'm Alexis, and this is Crash Course Botany. [THEME MUSIC] Botany is the scientific study of plants. That includes the huge ones, like towering 300-foot tall coastal redwood trees, and the tiny ones, like Wolffia globosa: green globs the size of a candy sprinkle.
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It includes the tasty plants, like sweet corn and mangoes; the super-stinky plants, like the corpse flower; and the super-stinky and tasty plants, like the durian. There are plants that look like brains, plants that look like rocks, even plants that look like Demogorgons. Botany is all about this kaleidoscope of plant life. It's the science of plants' structure and their function, the way their parts work and how their genetic traits pass on. But it's also about plants' relationship to other living things, including us. And it's no overstatement to say our lives —and the lives of every other creature on Earth— depend on plants. You've probably heard of photosynthesis, the chemical process that plants use to turn water, sunlight, and carbon dioxide into energy for them to live on. Well, the oxygen that comes out of that process is a byproduct, or something that's made by the nature of the process, not on purpose. And that incidental byproduct just happens to be the thing we evolved to breathe. Which, when you stop to think about it, is pretty amazing. Plants also cycle water and nutrients that all living things need between the soil and the atmosphere and back again. Even a single tree can be an all-in-one bed-and-breakfast for dozens of organisms. Like a fully alive combination Airbnb and Taco Bell. In fact, once you start noticing how deep this "plants are connected to everything" business goes, it's hard to stop. Plants are not just in your garden or your bathtub or the woods behind your house. They're in nearly everything. Let's head to the Thought Bubble... From the moment you wake up, you're already in touch with plants —because you spent all night wrapped up in sheets made of cotton fibers. Stumble into the shower, and plants are there, too. You grab a luffa, which is actually a dried-out tropical gourd. Give yourself a scrub and you come out smelling like a rose —because the oils in your soap came from roses.
