Scientific classification

Domain: Eukaryota
Unranked: Archaeplastida
Kingdom: Plantae

Our planet is home to almost 325,000 plant species. "Green Plants" are all the plants that contain chlorophyll which absorbs sunlight and makes sugar from water and carbon dioxide through the process of photosynthesis. Some parasitic plants live off of other plants, having lost their ability to photosynthesize. While some plants have asexual reproduction, most of them use sexual reproduction.

Plants are important to humans: most of the molecular oxygen in our world comes from green plants that absorb carbon dioxide and exhale oxygen. Plants that produce vegetables, fruits and grains provide the major source for the human diet. They provide an invaluable contribution to medicine. And the current catchphrase: plants assist in the alleviation of global warming. Green plants are grouped into 3 types: vascular plants that have an internal plumbing system (flowering plants, conifers, ferns, horsetails, club mosses), green algae (diatoms, stoneworts, green seaweeds) and bryophytes that are small enough not to need internal plumbing (mosses, liverworts, hornworts).