Howland, Jared , Farruggia, Frank T. .
Biogeography and phylogenetic history of the spiny Solanum section Crinitum (Solanaceae).
The phylogenetic relationships within the South American Solanum sect. Crinitum (Solanaceae) suggest that biogeographic data may aid in explaining unclear relationships. This study utilizes geographic coordinate data provided or estimated from the locality descriptions on herbarium specimens. Coordinate data was imported into ArcMap to represent the distribution of each species throughout it's native range. Within South America the distribution of sect. Crinitum can be generalized into widely distributed taxa and narrow endemics. The narrow endemics are restricted either to specific sub-Andean forests or to the northeastern habitats of Guyana, French Guyana, Suriname, and Brazil. Widely distributed taxa either span the Amazon Basin and adjacent floras, or the Brazilian cerrado and subtropical humid forests of southeastern Brazil, or are found throughout the Andes. A database of global climate data (WORLDCLIM) was evaluated to investigate potential climatic characteristics that correspond to the species distributions. The results revealed that certain plant species have distinct climatic constraints while others are orographically isolated within similar climatic conditions. Within the poorly resolved Andean clade the morphologically similar taxa S. wrightii, S. urticans, and S. grandiflorum have narrow and distinct distributions, while S. acanthodes and S. quaesitum are broadly distributed. There were no climatic variables distinguishing their distributions, however the narrow distributions can be attributed to isolated sub-montane valleys separated by high ridges. Similarly, S. sycophanta was found to be restricted to mid-elevation (900-2800 m) Andean forests, while the remaining species of sect. Crinitum are found mainly at lower elevations (0-1200 m). Utilizing the elevation data at a finer scale aided in defining the limits of the broadly distributed S. crinitum, S. gomphodes, and S. lycocarpum. Further study of temperature also correlated with the geographic distinctiveness of these taxa. These results indicate that closely related taxa within sect. Crinitum share similar distributions which can be defined by current climatic or orographic features of the landscape, and that these biogeographic features may help to resolve phylogeny and taxonomy.
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1 - Univerisity of Utah, Biology, 257 S 1400 E Room 201, Salt Lake City, UT, 84112, USA
Presentation Type: Poster:Posters for Sections
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM