Reassignment of Species of Paraphyletic Junellia s. l. to the New Genus Mulguraea (Verbenaceae) and New Circumscription of Genus Junellia : Molecular and Morphological Congruence

Abstract

Verbenaceae tribe Verbeneae includes three major genera, Verbena, Glandularia, and Junellia, which form a recently diversified group. Junellia is a South American genus, whereas Verbena and Glandularia are distributed in temperate regions of both South and North America. Seven non-coding chloroplast regions were sequenced including intergenic spacers and/or introns in trnD-trnT, trnS-trnG, trnS-trnfM, trnT-trnL, trnG, trnL, and trnL-trnF; the nuclear ITS and ETS regions were also sequenced. Together with previous studies, these results suggest that Junellia, as traditionally conceived, is a paraphyletic group of two separate clades. Junellia should be restricted to the clade containing the type, J. micrantha, which also includes Glandularia subgenus Paraglandularia and the genus Urbania. Consequently Urbania and Glandularia subgenus Paraglandularia are reduced to synonymy under Junellia, and eight new combinations in Junellia are proposed: Junellia ballsii, J. crithmifolia, J. fasciculata, J. hookeriana, J. lucanensis, J. occulta, J. pappigera and J. origenes. The remaining Junellia species form a monophyletic group here designated as the new genus Mulguraea, with 13 new combinations: Mulguraea arequipense, M. asparagoides, M. aspera var. aspera, M. aspera var. longidentata, M. cedroides, M. cinerascens, M. echegarayi, M. hystrix, M. ligustrina var. ligustrina, M. ligustrina var. lorentzii, M. scoparia, M. tetragonocalyx and M. tridens. Verbena and Glandularia s.s. are both monophyletic based on ETS/ITS data, but neither is monophyletic based on cpDNA data. Relationships within each genus are still not wholly resolved, nevertheless there is evidence that South and North American Verbena might both be monophyletic. Verbena and Glandularia are sister groups, and together they are sister to the reconstituted Junellia. Mulguraea is sister to the group comprising all the three genera, Verbena, Glandularia, and Junellia.