ItemArticle

Out of South America Into India: Unusual Long Distance Dispersal of a Plant GenusLepidagathis (Acanthaceae)

Title
Out of South America Into India: Unusual Long Distance Dispersal of a Plant GenusLepidagathis (Acanthaceae)
Creator
Surveswaran, Siddharthan; Agarwala, Kuldeep P.; Somani, Shriti; Bhagyasree Raveendran, V.R.; Vasudha, Sangoji; Toms, Ashna
Description
Background: Lepidagathis Willd. (Barlerieae, Acanthoideae, Acanthaceae) is a pantropical plant genus with about 156 species. Classification of Lepidagathis and Lophostachys has been under debate for long. The genus is mainly Asian in distribution, followed by Africa, with an odd distribution of over a quarter of its diversity in the Neotropics. Aims: Given its pantropical distribution, we hypothesised that this pattern may be due to long distance dispersal followed by radiation in either the Old World or New World. Therefore, we aimed to test the monophyly of the Old World and New World species and trace its ancestral area using molecular dating and biogeographical analysis. Materials and Methods: We used 28 Lepidagathis sensu lato (s.l.) species, with seven molecular markers (ITS, trnL-LF, trnSG, trnGR, psbA-trnH, rps16 and rbcL), and conducted single-gene phylogenies. Later, we used a concatenated dataset of five markers (ITS, trnL-LF, trnSG, trnGR and rps16) to perform molecular dating based on secondary calibration as well as primary calibration. For historical biogeography, we applied two schemes: one treating peninsular Indiahome to about 35 speciesas a distinct region, and another grouping it with Southeast Asia. Results: Our study of the 28 species resolved Lepidagathis into three well-supported clades and supported its broad circumscription (sensu lato), including the former Lophostachys. The combined gene phylogeny places the African monotypic genus Schaueriopsis variabilis and the Asian genus Chroesthes within Lepidagathis s.l. Historical biogeography under the DIVALIKE+J model identified Africa as the most likely ancestral area for the genus, with Indian endemic species derived from Neotropical ancestors. In an alternative scheme, which included India within Asia, it was inferred that Lepidagathis s.l. has evolved from Asia, with all three lineages within Lepidagathis s.l. also with Asian ancestry. Discussion: The timing of the dispersal events out of Africa into the neotropics, and dispersal into the paleotropics, was during the late Oligocene, suggesting that it must have been long-distance dispersal, as there were no land bridges connecting the Americas with the Old World. Conclusion: This phylogenetic study, together with the biogeographical analysis demonstrates that Lepidagathis and Lophostachys represent independently evolving lineages that can be recognised as distinct subgenera. Moreover, Lepidagathis s.l. provides strong evidence for long-distance intercontinental dispersal events, inferred to have occurred during the late Oligocene. Our biogeographical analysis, along with the genus's greatest species diversity in Asia, supports an Asian origin for Lepidagathis as the more plausible scenario. 2026 John Wiley & Sons Ltd.
Source
Journal of Biogeography;Volume;53;Issue;3;Article No.;e70170;
Date
01-01-2026
Publisher
John Wiley and Sons Inc
Subject
Acanthaceae; genetic diversity; intercontinental disjunction; Lophostachys; Oligocene; peninsular India; plastid intergenic spacers
Coverage
Surveswaran S., Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Telangana, Hyderabad, India; Agarwala K.P., Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Telangana, Hyderabad, India, Department of Life Sciences, CHRIST (Deemed to be University), Karnataka, Bangalore, India; Somani S., Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Telangana, Hyderabad, India, Department of Life Sciences, CHRIST (Deemed to be University), Karnataka, Bangalore, India; Bhagyasree Raveendran V.R., Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Telangana, Hyderabad, India; Vasudha S., Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Telangana, Hyderabad, India; Toms A., Department of Botany, University of Calicut, Kerala, Malappuram, India
Rights
Restricted Access; Hardcopy may be available in the library
Relation
ISSN: 3050270; CODEN: JBIOD
Format
online
Language
English
Type
Article

Citation

Surveswaran, Siddharthan; Agarwala, Kuldeep P.; Somani, Shriti; Bhagyasree Raveendran, V.R.; Vasudha, Sangoji; Toms, Ashna, “Out of South America Into India: Unusual Long Distance Dispersal of a Plant GenusLepidagathis (Acanthaceae),” CHRIST (Deemed To Be University) Institutional Repository, accessed June 20, 2026, https://archives.christuniversity.in/items/show/22976.

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