Systematics Section / ASPT
Zomlefer, W. B. , Whitten, W. M. , Judd, Walter S. , Williams, N. H. .
Infrageneric phylogeny of Schoenocaulon (Liliales: Melanthiaceae) with clarification of cryptic species based on ITS sequence data and geographical distribution.
As currently defined, the 24 species of Schoenocaulon occur in two disjunct areas: north central Florida (one species, S. dubium) and the region from southeastern New Mexico-Texas south to Venezuela and Peru. The 20 species endemic to Mexico are geographically restricted, often to a single mountain range. Schoenocaulon is a monophyletic genus, well supported by several morphological synapomorphies: the distinctive fibrous-tunicate bulb (covered by dark brown to black scales and fibers); the relatively long, bottlebrush-like spicate inflorescence of tiny, sessile to subsessile flowers with conspicuously exserted stamens; and winged seeds. However, species delimitations, often based on tepal morphology, have been problematic in this odd genus. Our analyses of ITS sequence data for all 27 species and infraspecific taxa support recognition of several new species, as well as recircumscription and placement of elements of the polyphyletic S. ghiesbreghtii complex. By applying phylogenetic species concepts to taxa with adequate sampling, we also infer 12 cladospecies and three to six metaspecies. The resolved phylogeny, correlated with geography and morphology, allows insight into the evolution of some unusual morphological characters within the genus, such as nectary differentiation and tepal margin type.
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Phylogeny of the Melanthiaceae
1 - University of Georgia, Department of Plant Biology, 2052 Miller Plant Sciences Building, Athens, Georgia, 30602-7271, USA
2 - University of Florida, Florida Museum of Natural History, Po Box 117800, Gainesville, Florida, 32611-7800, USA
3 - University of Florida, Department of Botany, 220 Bartram Hall, P.O. Box 118526, Gainesville, Florida, 32611-8526, USA
Presentation Type: Oral Paper
Location: Salon J - Austin Grand Ballroom/Hilton
Date: Monday, August 15th, 2005
Time: 9:00 AM