The Root of Angiosperm Phylogeny Inferred from Duplicate Phytochrome Genes

Abstract
An analysis of duplicate phytochrome genes ( PHYA and PHYC ) is used to root the angiosperms, thereby avoiding the inclusion of highly diverged outgroup sequences. The results unambiguously place the root near Amborella (one species, New Caledonia) and resolve water lilies (Nymphaeales, ∼70 species, cosmopolitan), followed by Austrobaileya (one species, Australia), as early branches. These findings bear directly on the interpretation of morphological evolution and diversification within angiosperms.