Phylogenetic Patterns, Evolutionary Trends, and the Origin of Ant–Plant Associations in Piper section Macrostachys: Burger’s Hypotheses Revisited

ered eight of the Piper species that occur in Costa Rica to make up the P. obliquum complex, and six additional species to be closely allied to it (Fig. 9.1; Burger 1971). Piper calcari-formis, an additional species assignable to the P. obliquum complex, was later described b