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Tackling convergent evolution, radiation and paraphyly: towards a modern classification of the giant genus Cyperus

Boekbijdrage - Boekabstract Conferentiebijdrage

Recent plant systematic research of Cyperus and its related genera resulted in new insights. The goal is to obtain a classification of Cyperus s.l. reflecting natural relationships. Based on molecular phylogenetic research, Cyperus s.l. is monophyletic (= the Cyperus clade), but Cyperus s.s. is paraphyletic since part of its species were placed in segregate genera. At the base, Cyperus s.l. species using C3 photosynthesis form a paraphyletic grade (= C3 Cyperus). All C4 Cyperus s.l. species form a single monophyletic clade (= C4 Cyperus) nested in C3 Cyperus. While relationships in C3 Cyperus are clear, some relationships in C4 Cyperus are not well resolved due to species radiation coinciding with the evolution of the C4 photosynthetic pathway. Reconstruction of evolutionary relationships in the Cyperus clade is not only complicated by species radiation, but also by convergent evolution of characters. We now know that characters previously used for generic delimitation originated multiple times independently (e.g. spiral glumes, single-flowered spikelets and laterally flattened nutlets). Based on the current knowledge, we decided to lump the segregate genera into a broadened, monophyletic genus Cyperus. In the genus Cyperus, we now recognize two subgenera corresponding to C3 Cyperus and C4 Cyperus. Within these subgenera sections are placed, some of which correspond to the old segregate genera. We systematically re-evaluate the boundaries of the existing sections, in order that they become monophyletic taxa. As a consequence of lumping the segregate genera into Cyperus, all species from the segregate genera are now receiving a Cyperus name.
Boek: MONOCOTS V, New York 2013 : 5th international conference on comparative biology of monocotyledons : abstracts
Pagina's: 67 - 68
Jaar van publicatie:2013