Systematic placement and biogeographical relationships of the monotypic genera Gypothamnium and Oxyphyllum (Asteraceae: Mutisioideae) from the Atacama Desert |
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Authors: | FEDERICO LUEBERT JUN WEN MICHAEL O DILLON |
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Institution: | 1. Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Chile, Casilla 9206, Santiago, Chile;2. Freie Universit?t Berlin, Institut für Biologie – Systematische Botanik und Pflanzengeographie, Altensteinstra?e 6, D‐14195 Berlin, Germany;3. Department of Botany, National Museum of Natural History, MRC‐166, Smithsonian Institution, PO Box 37012, Washington DC 20013‐7012, USA;4. Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 10093, China;5. Botany Department, The Field Museum, 1400?S. Lake Shore Dr., Chicago, IL 60605, USA |
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Abstract: | Gypothamnium and Oxyphyllum (Asteraceae) are two monotypic genera endemic to the Atacama Desert of northern Chile. We performed a phylogenetic analysis using published sequences of the plastid rbcL and ndhF genes, the trnL‐trnF region and the nuclear ribosomal internal transcribed spacer (ITS) to assess the systematic placement of the two genera within Mutisioideae. On the basis of the phylogenetic results, we constructed area cladograms to explore the biogeographical relationships and origin of the genera. The phylogenetic analysis showed that Gypothamnium is closely related to Aphylloclados, Plazia, Urmenetia, Lycoseris and Onoseris, whereas Oxyphyllum is closely related to Leucheria, Moscharia, Polyachyrus and, with low support, Jungia. These results do not differ substantially from those proposed in previous treatments based on morphological characters. The biogeographical analysis suggests that Gypothamnium in the coastal Atacama Desert is related to taxa that are currently distributed in eastern subtropical South America and in the Puna. Oxyphyllum may have originated from central Chile and other areas in southern South America, but its sister group (Leucheria + Polyachyrus) also reaches the Puna and the coastal Atacama Desert. Both groups show ancestral affinities with elements currently distributed in north‐western South America and Mesoamerica. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 32–51. |
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Keywords: | arid environments Chile Compositae phylogeny South America |
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