| Abstract Detail
Systematics Section / ASPT Kiel, Carrie A. [1], Manktelow, Mariette [2], Daniel, Thomas F. [3], Andreasen, Katarina [4], Holmqvist, Per-Henrik [2], McDade, Lucinda A. [1]. Bird Pollination has evolved multiple times in the Tetramerium group (Tetramerium Lineage, Justicieae, Acanthaceae). Morphology and preliminary molecular data support monophyly of a sublineage within the Tetramerium lineage comprising about 70 species belonging to seven genera: Anisacanthus, Aphanosperma, Carlowrightia, Gypsacanthus, Henrya, Mexacanthus, and Tetramerium (here designated as the Tetramerium group). Our goals were to test this hypothesis and to study the evolution of pollination and associated changes in corolla morphology within the group. Four closely related genera were added as out-groups: Chalarothyrsus, Hoverdenia, Mirandea, and Yeatesia. The molecular data set includes sequences for the nrITS region, and the cp trnG-S and trnT-L spacers for a total of nearly 3000 aligned bases. We also studied pollination biology and corolla morphology. Our results support monophyly of a modified Tetramerium group that includes Chalarothyrsus but excludes South American species of Anisacanthus. A morphological synapomorphy for this clade is having the stamens positioned ventrally, adjacent to the lower lip of the corolla. Within the Tetramerium group, North American species of Aniscanthus are monophyletic with inclusion of Mexacanthus. Notable similarities in corolla morphology between Mexacanthus and Anisacanthus corroborate this result. Most species of Tetramerium form a monophyletic group except that T. sagasteguianum is distant from this group. Carlowrightia is grossly polyphyletic, with species distributed among at least three distinct lineages. Bird pollination has evolved at least four times within the group. We also report discovery of a unique nectar barrier in the corollas of flowers of North American bird-pollinated species of Anisacanthus.
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1 - Academy of Natural Sciences, Department of Botany, 1900 Benjamin Franklin Parkway, Philadelphia, Pennsylvania, 19103, USA
2 - Uppsala University, Systematic Botany, Department of Evolution, Genomics and Systematics, Norbyvägen 18 D, Uppsala, SE-752 36, Sweden
3 - California Academy of Sciences, Department of Botany, 875 Howard Street, San Francisco, California, 94103-3009, USA
4 - Uppsala University, Systematic Botany, Department of Evolution, Genomics and Systematics, Norbyvägen 18D, Uppsala, SE-752 36, Sweden
Keywords:
Tetramerium lineage
Acanthaceae
nrITS
cp trnG-S
cp trnT-L
pollination evolution
Phylogenetics.
Presentation Type: Poster
Session: 33-102
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM
Abstract ID:226 |
