Abstract Detail

Systematics Section/ASPT

Sweeney, Patrick [1], Clement, Wendy [2], Madriñán, Santiago [3], Torres, Luis Felipe [3], Donoghue, Michael [4].

A putative Andean plant radiation revisited: a new understanding of South American Viburnum.

Viburnum (Adoxaceae, Dipsacales) is a flowering plant clade of ~165 woody species distributed primarily in temperate forests around the Northern Hemisphere, but with significant extensions into the mountains of Latin America and Southeast Asia. Extensive molecular phylogenetic studies have set the stage for a comprehensive monographic treatment of Viburnum. These studies imply that all of the South American taxa form a clade comprised of a group of morphologically similar entities occupying mid- to upper-montane forests in the Andes of Venezuela, Colombia, Ecuador, Peru, and Bolivia. The most recent taxonomic treatment of South American Viburnum was published in 1930 by Killip and Smith who recognized 29 species and seven infraspecific taxa. Since that time the total number of species has increased to 34. As part of our world-wide monograph of the genus, we have re-examined species circumscriptions of South American Viburnum. We carried out field work in Colombia and Ecuador, examined numerous herbarium specimens from major relevant herbaria, and conducted molecular phylogenetic studies of the group. Based on our data, and knowledge of geographic distributions, we make a four-fold reduction in the number of recognized species. Our studies show that many of the characters utilized by Killip and Smith and other authors to delineate species are highly variable within and among individual plants and populations, with considerable overlap among putative species. Furthermore, there were few South American Viburnum specimens available for study by Killip and Smith and many species in their treatment were represented by only one or a few specimens. Our results, coupled with phylogenetic analyses showing little divergence among tips within the clade and the recent origin of the Andean habitats occupied by Viburnum, indicate that South American Viburnum are recently diverging and that lineages within the clade are in the process of differentiating.

1 - Yale Peabody Museum of Natural History, Division of Botany, 170 Whitney Avenue, New Haven, CT, 06511, USA
2 - The College Of New Jersey, Biology, 2000 Pennington Road, Department Of Biology, Ewing, NJ, 08638, USA
3 - Universidad de los Andes, Departamento de Ciencias Biológicas, CL 18-2 68, Bogotá, D.C., 111711, Colombia
4 - Yale University, Department Of Ecology And Evolutionary Biology, 21 Sachem Street, PO BOX 208105, New Haven, CT, 06511, USA

Keywords:
Viburnum
Adoxaceae
systematics
monograph
Andes
South America.

Presentation Type: Oral Paper:Papers for Sections
Session: 45
Location: River Fork/Grove
Date: Wednesday, July 30th, 2014
Time: 5:00 PM
Number: 45014
Abstract ID:450
Candidate for Awards:None