|Croat, Thomas - MISSOURI BOTANICAL GARDEN|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2003
Publication Date: April 2, 2003
Citation: Meerow, A.W., Croat, T.B. 2003. Phylogeny of neotropical Homalomena schott (Araceae) based on plastid trnL-F and nRDNA ITS sequences. Third International Conference on the Comparative Biology of the Monocotyledons. Interpretive Summary: NOT APPLICABLE.
Technical Abstract: The genus Homalomena is one of three genera of Araceae that have a puzzling disjunct distribution between southeast Asia and tropical America. The genus consists of ca. 110 species of rain forest herbs, usually with an anise-like foliar scent, and is most speciose in Asia. The American species were formally recognized as section Curmeria by Engler. The genus is classified within tribe Homalomeneae, along with the SE Asian Furtadoa, but the exact position of the tribe in relation to the rest of the family has differed in recent accounts. We obtained plastid trnL-F sequences for four Asian species and thirteen accessions representing nine taxa of American Homalomena and analyzed them cladistically using Philodendron insigne and Anubias barteri as outgroups. The American Homalomena resolve as a monophyletic sister clade to the Asian species. H. erythropus, H. hammelii and H. speariae form a distinct clade. H. picturata and H. peltata (from multiple sources of different geographic origin) do not resolve as monophyletic, suggesting that segregate species may need to be recognized. The results of analysis of ITS sequences from the same American taxa with the Australasian H. pygmaea used as outgroup is largely in congruence with the results from plastid trnL-F. High base substitution rates within ITS between the subclades of American Homalomena might suggest a long evolutionary history for the genus and possible isolation of ancestral populations.