XVI International Botanical Congess

The genus Bursera (Burseraceae) is one of the most diversified and abundant groups of the tropical dry forests of Mexico. We reconstructed a phylogeny of 57 species and varieties using nucleotide sequences of the ITS region of nuclear ribosomal DNA. As outgroups we used four species of the allied genera Commiphora and Boswellia and one species of Spondias (Anacardiaceae). Our results support the view that Bursera is monophyletic. The division of Bursera into sections Bullockia and Bursera is also strongly supported by our phylogeny. Several other subclades also had high bootstrap values especially within section Bursera. We use the phylogeny as a basis for discussing evolutionary tendencies in bark, leaves, breeding systems, and fruits.