Amborella is a monotypic genus of understory shrubs or small trees endemic to the main island, Grande Terre, of New Caledonia in the southwest Pacific Ocean. The genus is the only member of the family Amborellaceae and the order Amborellales and contains a single species, Amborella trichopoda. Amborella is of great interest to plant systematists because molecular phylogenetic analyses consistently place it as the sister group to all other flowering plants; as a result, it is critical for understanding angiosperm evolution. It is understood to be the most basal extant flowering plant, and is one of several groups treated as "basal angiosperms".
A key mechanism that lets flowering plants open their stomata wide — and thus grow faster and more productively — originated once, in the very first flowering plant ancestor, and has been present in all angiosperms ever since. This trait likely enabled the explosive success of flowering plants on Earth.