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Callitriche (Plantaginaceae) is a cosmopolitan plant genus in shallow lakes and river margins, wetlands, ditches and temporary pools. Its species exhibit considerable diversity in growth habit, aquatic (submerged), amphibious and terrestrial, but the polarity of growth habit evolution to or from terrestrial habitats is yet to be addressed. The origin of its cosmopolitan distribution, especially to or from Australasia, remains uncertain. We assessed evolution of growth habit and inferred biogeographic history in a phylogenetic framework using DNA sequence data from plastid DNA and the nuclear internal transcribed spacer region. These were separately analysed using maximum parsimony, maximum likelihood and Bayesian inference. The multilocus data sets, excluding two species exhibiting conflicting placement, were then used for coalescent-based species-tree analysis and the resulting species tree was used for ancestral state reconstruction and biogeographic inference. We obtained moderately resolved phylogenetic trees, showing that two terrestrial species, one from Australasia and the other from temperate and tropical Asia, are the first diverging species and the remaining terrestrial species are scattered across the trees. The ancestral state reconstruction supports a terrestrial origin of the genus and multiple reverse transitions to terrestrial conditions. The biogeographic results suggest a Northern Hemisphere origin with multiple dispersal events to Australasia or an out-of-Australasia scenario and rather recent, multiple dispersal events back to Australasia. [ABSTRACT FROM AUTHOR]

Maximum likelihood and Bayesian inference analyses of nuclear ribosomal DNA ( ETS1f) and plastid DNA ( rpl32-trnL, trn H-psb A) sequence data are presented for ' C4 Cyperus' ( Cyperaceae). The term ' C4 Cyperus' encompasses all species of Cyperus s.l. that use C4 photosynthesis linked with chlorocyperoid vegetative anatomy. Sampling comprises 107 specimens of 104 different taxa, including many of the subdivisions of C4 Cyperus s.s. and all C4 segregate genera ( Alinula, Ascolepis, Kyllinga, Lipocarpha, Pycreus, Queenslandiella, Remirea, Sphaerocyperus and Volkiella). According to our results, C4 Cyperus is a well-supported monophyletic clade nested in C3 Cyperus. Despite the lack of resolution along the backbone of the C4 Cyperus clade and for some internal branches, several well-supported clades can be distinguished. The first clade in C4 Cyperus is formed by Cyperus cuspidatus and C. waterloti. Other recognizable and well-supported clades correspond to segregate genera, i.e. Ascolepis, Lipocarpha including Volkiella, and Kyllinga. Species of C4 Cyperus s.s. form a core grade in which the C4 segregate genera are embedded. Pycreus, the largest segregate genus composed of c. 120 species, is not monophyletic as it includes several C4 species of Cyperus s.s. This study establishes a phylogenetic framework for revising the classification and character evolution in Cyperus s.l. © 2013 The Linnean Society of London [ABSTRACT FROM AUTHOR]

Maximum likelihood and Bayesian analyses of nrDNA (ETS1f) and plastid DNA ( rpl32-trnL, trnH-psbA) sequence data are presented for 'C3 Cyperus' (Cyperaceae). The term 'C3 Cyperus' indicates all species of Cyperus s.l. that use C3 photosynthesis linked with eucyperoid vegetative anatomy. Sampling comprises 77 specimens of 61 different taxa, representing nearly all previously recognized subdivisions of C3 Cyperus and the segregate genera Courtoisina, Kyllingiella and Oxycaryum. According to our results, the Cyperus clade is divided in six well-supported clades. The first of these clades (clade 1) forms three subclades largely corresponding to Cyperus sections Haspani, Incurvi and Diffusi. Clade 2 comprises the entirely New World C. section Luzuloidei sensu Denton (1978). Clade 3 is a highly diverse clade including two subclades: clade 3a, C. sections Pseudanosporum and Anosporum plus the segregate genera Courtoisina and Oxycaryum; and clade 3b, C. section Fusci. Clade 4 corresponds to C. section Alternifolii and clade 5 to C. section Leucocephali plus the segregate genus Kyllingiella. The sixth clade is a well-supported monophyletic clade encompassing all C4 Cyperus s.l. species ('C4 Cyperus'). This study establishes a phylogenetic framework for future studies. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167, 19-46. [ABSTRACT FROM AUTHOR]