XVI International Botanical Congess

Uncinia (c. 65 spp.) is one of six genera in the Cariceae, a taxonomically difficult tribe whose phylogeny is confounded by floral reduction and poor circumscription. Classifications of Cariceae and Uncinia share several traits, they rely on gross inflorescence morphology, phytogeography, and assumptions of reductive evolution. A phylogeny of Uncinia is thus of paramount interest as a model on how to approach tribal classification and evolution. Phylogenetic analyses indicate that Uncinia divides into two major groups: (1) a western Pacific clade consisting of sect. Uncinia species, and (2) a South American/western Pacific clade that consists of a core South American group (sect. Uncinia and Platyandrae) with elements of sect. Uncinia at its base. This topology suggests that the characters used to circumscribe sect. Uncinia may be primitive. Furthermore, all of the currently recognized series are either poly- or paraphyletic. Sequence analyses indicate that in the Cariceae ETS evolves at a similar rate to ITS.