Key points are not available for this paper at this time.
Abstract The genus Andrographis is predominantly peninsular Indian distribution after the resurrection of Haplanthus which is predominantly southeast Asian in distribution. Previous study have shown its close phylogenetic affinity with Haplanthodes and Haplanthus. In this study we constructed a most comprehensive phylogeny of the tribe Andrographideae using five plastid regions, rbcL, matK, trnLF, psbA-trnH and trnGR. The results show polyphyly between Andrographis, Haplanthodes and Haplanthus, resulting in a Andrographis sensu lato (s.l.) clade. Within this earliest splitting clade consisted of Andrographis and Haplanthus ovatus. The next split was with Haplanthodes followed by Andrographis sensu stricto (s.s) clade. Within the Andrographis clade, we observed two clades one was western in distribution and the other was eastern in distribution in peninsular India. Biogeographical analysis suggested an eastern peninsular Indian origin of Andrographis and followed by dispersal into the relative wetter western peninsular India. We deduced the time of diversification of the clades of Andrographis. We discuss the role of south Asian winter monsoon in the diversification of Andrographis which has adapted to aridity.
Surveswaran et al. (Mon,) studied this question.