The Anthophyta are the flowering plants, and are the largest and most diverse group of plants today. They are usually divided into two groups based on the number of cotyledons on the embryo. Those flowering plants with two cotyledons are called dicots while those with only one are called monocots. Current hypotheses about the origin and diversification of the flowering plants suggest that the dicots are the older group, from which the monocots evolved. In fact, some dicots, called paleoherbs, are now believed to be closer relatives of the monocots than of the other dicots. You can read about the morphological differences between monocots and dicots from our special exhibit.
For more information on current thought in angiosperm systematics, visit the Tree of Life.