Basal Angiosperms

The basal angiosperms are the first flowering plants to diverge from the ancestral angiosperm. In particular, the most basal angiosperms were called the ANITA grade which is made up of Amborella (a single species of shrub from New Caledonia), Nymphaeales (water lilies, together with some other aquatic plants) and Austrobaileyales (woody aromatic plants including star anise). ANITA stands for the Amborella, Nymphaeales and Illiciales, Trimeniaceae-Austrobaileya. Some authors have shortened this to ANA-grade for the three orders, Amborellales, Nymphaeales, and Austrobaileyales, as the order Illiciales was reduced to the family Illiciaceae and placed, along with the family Trimeniaceae, within the Austrobaileyales.

The basal angiosperms are only a few hundred species, compared with hundreds of thousands of species of eudicots, monocots or magnoliids. They diverged from the ancestral angiosperm before the five groups comprising the mesangiosperms diverged from each other.