| Abstract Detail
Systematics Section Simmons, Mark P. [1], Coughenour, Jennifer M. [1], Lombardi, Julio A. [2], Yakobson, Kendra [1], Archer, Robert H. [3]. Phylogeny of Celastraceae subfamily Hippocrateoideae inferred from morphological characters and nuclear and plastid genes. The phylogeny of Celastraceae subfamily Hippocrateoideae (~100 species and 19 genera in the Old and New World tropics) was inferred using morphological characters together with plastid (matK, trnL-F) and nuclear (ITS and 26S rDNA) genes. The subfamily is easily recognized by the two synapomorphies of having transversely flattened, deeply lobed capsules and seeds with membranous basal wings or narrow stipes together with bisexual, 5-merous flowers that generally have an extrastaminal disk and three stamens. Hippocrateoideae, like Salacioideae, are inferred to have an Old World origin. The narrow stipes of Neotropical species that are water-dispersed are inferred to be derived within the subfamily from ancestral species with wind-dispersed winged seeds. Helictonema, a monotypic genus endemic to tropical Africa, has a small, white, spongy aril that is located at the base of the seed wing and appears to be unique within Hippocrateoideae. Our inference that Helictonema is sister to the remaining members of the subfamily, considered in the context of Sarawakodendron being sister to Salacioideae, suggests that small arils and capsular fruit were primitive within both subfamilies. The aril became dramatically enlarged within Salacioideae, for which the fruits are berries, and lost entirely within Hippocrateoideae, for which the fruits are transversely flattened capsules.
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1 - Colorado State University, Department of Biology, Fort Collins, Colorado, 80523-1878, U.S.A.
2 - Instituto de Biociências de Rio Claro, Departamento de Botânica, Universidade Estadual Paulista - UNESP, São Paulo, Brazil
3 - South African National Biodiversity Institute, National Herbarium, Private Bag X101, Pretoria, 001, Republic of South Africa
Keywords:
aril homology
Helictonema
Hippocrateoideae
seed wing.
Presentation Type: Oral Paper:Papers for BSA Sections
Session: 57
Location: Maybird/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 8:45 AM
Number: 57004
Abstract ID:260 |
