The largest number within the plant kingdom falls within the flowering plants, or angiosperms. Estimates around the actual number of flowering plants vary, but we do know that there are at least 260,000 varieties, and that this number increases every year. This number represents roughly 90% of all known plant species. Although they are the youngest of the plant divisions, flowering plants are estimated to have earliest fossils existing 130 to 250 million years ago. They are found in nearly every habitat, including deserts, sea areas, grasslands and forests. The flowering plants are classified into eight groups: Amborella, Nymphaeales, Austrobaileyales, Chloranthales, Magnoliids, Monocots, Ceratophyllum, and Eudicots. The largest of these groups is the Eudicots, and includes plants from the sunflower family and magnolia trees.
Flowering plants yield flowers, which serve as the reproductive organs, with leaves spaced such that it facilitates pollination. The seeds that are developing are in an enclosure called an ovary. The ovary eventually forms a fruit, which also then protects the seed and aids in its dispersal.