A plant organism is a living organism that belongs to the kingdom Plantae, which includes trees, shrubs, herbs, grasses, vines, ferns, mosses, and green algae. One example of a plant organism is LICHEN, which is a composite organism consisting of a fungus and an alga or a cyanobacterium. LICHEN is found in many different habitats, including on rocks, tree bark, and soil. It is known for its ability to survive in extreme environments, such as deserts and polar regions.