McDade, Lucinda , Daniel, Thomas F. , Ocampo, Gilberto , Kiel, Carrie .
Relationships, Character Evolution, and Biogeographic Patterns in the Phylogenetically Pivotal Lineage Nelsonioideae (Acanthaceae s.l.).
Advances in knowledge of relationships among the large plant family Acanthaceae have established that Nelsonioideae are sister to the rest of the family (i.e., Thunbergioideae + Acanthoideae), albeit with sparse taxon sampling in recent phylogenetic analyses. Our present study seeks to delimit the clade, test monophyly of its constituent genera (and of subgeneric taxa within Staurogyne, the largest genus of nelsonioids), provide taxonomic revisions at the genus level and at the species level for the ca. 20 species of Elytraria, and document character evolution within Nelsonioideae and among lineages of Acanthaceae. Notably, nelsonioids lack the synapomorphies of core Acanthaceae and lineages therein (e.g., retinaculate fruits, cystoliths) and are key to understanding the evolutionary transitions that have yielded these shared derived traits. The group is also biogeographically noteworthy in that two genera, Elytraria and Staurogyne are pantropical; most small to medium-sized genera of Acanthaceae are limited to the Old or New World. In addition, Nelsonia, with a small but uncertain number of species, is nearly pantropical; these plants are somewhat weedy and may be introduced in parts of the current range. Results to date strongly support monophyly of Elytraria and Nelsonia; Anisosepalum and Saintpauliopsis are sister taxa and are together sister to the largest genus in the clade, Staurogyne (ca. 140 species). The monotypic genera Gynocraterium (New World) and Ophiorrhiziphyllon (Old World) appear to be nested within pantropical Staurogyne. Taxonomic and biogeographic implications of these results will be discussed.
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1 - Rancho Santa Ana Botanic Garden, 1500 North College Avenue, Claremont, California, 91711, USA
2 - California Academy of Sciences, Department of Botany, 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA, 94118, USA
3 - Rancho Santa Ana Botanic Garden, Botany, 1500 North College Avenue, Claremont, California, CA 91711, USA
4 - Rancho Santa Ana Botanic Garden, 1500 N. College Ave., Claremont, CA, 91711, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Rendezvous A/Snowbird Center
Date: Tuesday, July 28th, 2009
Time: 10:30 AM