Systematics Section / ASPT
Kiel, Carrie A. , McDade, Lucinda A. , Daniel, Thomas F. .
The species-rich and biologically diverse “justicioids” (Acanthaceae: Justicieae): phylogeny, biogeography, and morphological evolution.
MOLECULAR sequence data from nrITS, trnGS, trnTL, rps16, and trnLF regions were used to examine phylogenetic relationships among the morphologically disparate justicioid lineage within the large wide-ranging tribe Justicieae (Acanthaceae). This monophyletic lineage includes members of Justicia (ca. 700 species) and related genera from both the Old World (OW) and New World (NW). These plants share a number of morphological characteristics, in particular, the evolution of a rugula: a channel-like structure on the internal surface of the upper lip formed by parallel ridges of corolla tissue that partially enclose the style. Our results strongly support monophyly of NW justicioids, including all NW species of Justicia plus species traditionally assigned to at least five other genera. Further, with a greatly expanded taxon sample, we confirm our earlier unexpected result that the apomorphic lineage Diclipterinae is embedded within justicioids. As traditionally defined, Diclipterinae lack the morphological traits that link justicioids and thus have not previously been associated with them. Our current study further extends this unexpected result by placing a number of OW justicioids as a series of lineages basal to core Diclipterinae, with very strong support for these relationships. Thus, OW justicioids are placed in part with Diclipterinae and in part basal to (NW justicioids + expanded Diclipterinae). A number of genera of justicioids, notably those of core Diclipterinae, are monophyletic but Justicia is grossly polyphyletic and neither the NW nor OW species assigned to this genus comprise monophyletic lineages. Our phylogenetic results provide a context for examining biogeography, evolution of plant habit, corolla and pollen morphology, and pollinator relationships across this species-rich (at least 1000 species) and biologically disparate clade.
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1 - Academy of Natural Sciences, Department of Botany, 1900 Benjamin Franklin Parkway, Philadelphia, Pennsylvania, 19103, USA
2 - California Academy of Sciences, Department of Botany, 875 Howard Street, San Francisco, California, 94103-3009, USA
Presentation Type: Poster:Posters for Sections
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM