Phylogenetic and biogeographic approach to genus Flourensia (Asteraceae, Heliantheae).

JUAN CAMILO OSPINA; JOSÉ PANERO; SUSANA FREIRE; CAROLINA CORREA; SCATAGLINI, AMALIA; LONE AAGESEN

CABA

Congreso; XXXV Willi Hennig Society Meeting; 2016

MACN

The Neotropical genus Flourensia DC. (Asteraceae, Heliantheae) comprises 32 taxa with two diversity centers one in arid zones of southern South America and one in northern Mexico-southern USA. The same disjunction is found in several Angiosperm taxa (e,g., [Larrea (Zygophyllaceae), Prosopis, Prosopidastrum, Hoffmannseggia (Fabaceae), and Distichlis (Poaceae)] which has fuelled the discussion as to whether the flora of these biotas arose by vicariance or long distance dispersal. Phylogenetic studies available for some of the groups support the latter and furthermore suggest that long distance dispersalmay have happened repeatedly in some of these. In Flourensia, the presence of several narrow endemic species in the northern Argentina suggests limited dispersal ability. Analyzing how and when Flourensia obtained its disjunct distribution and diversified in arid regions of both southern and northern America is the aim of the present study. In South America, Flourensia species mainly occupy environments of the inter-Andean dry valleys from the southern depression of Huancabamba in Peru to central Argentina, with most of the species distributed in northern Argentina. Based on our parsimony analysis of Flourensiainferred from nuclear ITS and plastid trnL-F sequences, we study the geographical distributions of all species to determine whether the current disjunct distribution of the genus is due to one or several events.