Plants are living organisms that belong to the kingdom Plantae and include familiar organisms like trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants is called botany. Botanists have identified over 315,000 plant species, including 281,821 flowering plants, 12,000 ferns and allies, and 16,236 bryophytes. Green plants obtain most of their energy from sunlight through photosynthesis, which uses chlorophyll in chloroplasts to give plants their green color.