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Plant Science Today (PST)

Research Articles

Vol. 13 No. 3 (2026)

Comprehensive checklist of the flowering plants of the Agasthyamalai Biosphere Reserve, South India

DOI
https://doi.org/10.14719/pst.15465
Submitted
8 May 2026
Published
15-09-2026 — Updated on 30-09-2026
Versions

Abstract

The Agasthyamala Biosphere Reserve (ABR), situated at the southern extremity of the Western Ghats, represents one of the most important centres of tropical biodiversity and endemism in peninsular India. Despite more than a century of botanical exploration, information on its angiosperm diversity remains scattered across numerous floras, checklists, unpublished reports and continuously changing taxonomic databases, leading to inconsistencies in nomenclature and distributional records. The present study addresses this gap by providing a critically compiled and taxonomically updated checklist of the flowering plants of the ABR based on an extensive evaluation of original protologues, classical floras, recent literature and global taxonomic repositories following the Angiosperm Phylogeny Group IV classification system. The study documented 3261 species, 26 subspecies and 28 varieties belonging to 1139 genera and 190 families, making ABR one of the richest floristic regions in peninsular India. Fabaceae emerged as the most species-rich family with 349 taxa, followed by Rubiaceae (194 taxa), Poaceae (193 taxa) and Orchidaceae (168 taxa). A remarkably high level of endemism was recorded, with 1018 taxa (31.2 %) endemic to India, including 245 steno-endemic taxa confined to highly specialised habitats and narrow altitudinal zones. The flora also revealed strong biogeographic affinity with Sri Lanka, with 347 taxa shared between the two regions, highlighting the significance of the southern Western Ghats–Sri Lanka floristic province. The coexistence of ancient lineages and recently diversified endemic taxa indicates that the Agasthyamala landscape functions both as an evolutionary refugium and as an active centre of speciation. These findings reaffirm the exceptional ecological and evolutionary significance of the ABR and emphasise the vulnerability of its habitat-specific flora to ongoing anthropogenic pressures and climate change. The study provides an authoritative baseline for biodiversity assessment and demonstrates that effective conservation of the ABR requires targeted habitat protection, long-term monitoring and region-specific management strategies to safeguard one of the world's most important centres of tropical plant diversity.

References

  1. 1. Jha GK, Singh G, Vennila S, Hegde M, Rao MS, Panwar H. Multi-layer perceptron based neural network model predicting the maximum severity of Spodoptera litura (Fabricius) on groundnut in relation to the climate for Dharwad region of Karnataka (India). Mausam 2017; 68(3): 537–542. https://doi.org/10.54302/mausam.v68i3.708
  2. 2. Dutta K, Reddy CS, Sharma S, Jha CS. Quantification and monitoring of forest cover changes in Agasthyamala Biosphere Reserve, Western Ghats, India (1920–2012). Curr Sci. 2016;110(4):508–20. https://doi.org/10.18520/cs/v110/i4/508-520
  3. 3. Hooker JD, editor. The Flora of British India. Vol. 1–7. London: L. Reeve & Co.; 1872–1897.
  4. 4. Gamble JS. Flora of the Presidency of Madras. Vol. 1–3. London: Adlard & Son Ltd.; 1915–1936. https://doi.org/10.5962/bhl.title.21628
  5. 5. Nair NC, Henry AN. Flora of Tamil Nadu, India. Series 1: Analysis. Vol. 1. Coimbatore: Botanical Survey of India; 1983.
  6. 6. Henry AN, Chithra V, Balakrishnan NP. Flora of Tamil Nadu, India. Series 1: Analysis. Vol. 2. Coimbatore: Botanical Survey of India; 1987.
  7. 7. Henry AN, Chithra V, Balakrishnan NP. Flora of Tamil Nadu, India. Series 1: Analysis. Vol. 3. Coimbatore: Botanical Survey of India; 1989.
  8. 8. Mohanan N, Sivadasan M. Flora of Agasthyamala. Dehra Dun: Bishen Singh Mahendra Pal Singh; 2002.
  9. 9. Mohanan M, Henry AN. Flora of Thiruvananthapuram, Kerala. Kolkata: Botanical Survey of India; 1994.
  10. 10. Subramaniyan KN. Flora of Thenmala Division. Dehra Dun: International Book Distributors; 1995.
  11. 11. Nair KKN, Nayar MP. Flora of Courtallum. Vol. 1–2. Calcutta: Botanical Survey of India; 1986.
  12. 12. Mathew J, George KV. Flora of Achankovil forests, southern Western Ghats, India. Germany: LAP Lambert Academic Publishing; 2016.
  13. 13. Sathish Kumar C. Plants of Peppara and Neyyar Wildlife Sanctuaries (Unpublished). Thiruvananthapuram: Kerala Forest Department; 2002.
  14. 14. Manickam VS, Murugan C, Jeya Jothi G. Flora of Thirunelveli Hills. Vol. 1. Dehra Dun: Bishen Singh Mahendrapal Singh; 2008.
  15. 15. Sathish Kumar C, Santhosh Kumar ES, Suresh Kumar PC. Preliminary checklist of the plants of KMTR (Unpublished); 2002.
  16. 16. Matthew KM. The Flora of the Tamilnadu Carnatic. Vol. 1–3. Thiruchirappalli: Rapinat Herbarium, St. Joseph's College; 1983.
  17. 17. Sivadasan M, Anilkumar N, Ravi N. Flora of Pathanamthitta. Delhi: Daya Publishing House; 2005.
  18. 18. Sasidharan N. Studies on the flora of Shenduruney Wildlife Sanctuary with emphasis on endemic species. KFRI Research Report No. 128; 1997.
  19. 19. Nayar TS, Beegam AR, Mohanan N, Raj Kumar G. Flowering Plants of Kerala: A Handbook. Palode: Tropical Botanic Garden and Research Institute; 2006.
  20. 20. Nayar TS, Sibi M, Beegam AR. Flowering Plants of the Western Ghats. Vol. 1–2. Thiruvananthapuram: Jawaharlal Nehru Tropical Botanical Garden and Research Institute; 2014.
  21. 21. Narasimhan D, Irwin SJ. Database on Agasthyamala Biosphere Reserve. Report submitted to Department of Environment, Tamil Nadu. Chennai: Centre for Floristic Research, Department of Botany, Madras Christian College (Autonomous); 2017.
  22. 22. Richard PSS, Muthukumar SA. Arborescent angiosperms of Mundanthurai Range in the Kalakad-Mundanthurai Tiger Reserve (KMTR) of the southern Western Ghats, India. Check List. 2012;8(5):951–62. https://doi.org/10.15560/8.5.951
  23. 23. Viswanathan MB. Conservation of threatened plant resource of Kalakkad-Mundanthurai Tiger Reserve in India. Annual Report. Ministry of Environment and Forests of India; 1999.
  24. 24. Thothathri K. Studies in Leguminosae XXX: Further contributions to Dalbergia and Derris. J Bombay Nat Hist Soc. 1984;81:238–42.
  25. 25. Ahmedullah M, Nayar MP. Endemic Plants of the Indian Region. Vol. 1. Peninsular India. Kolkata: Botanical Survey of India; 1986. p. 261.
  26. 26. Nayar MP, Sastry ARK. Red Data Book of Indian Plants. Vol. 1. Kolkata: Botanical Survey of India; 1987.
  27. 27. Nayar MP, Sastry ARK. Red Data Book of Indian Plants. Vol. 2. Kolkata: Botanical Survey of India; 1988.
  28. 28. Nayar MP, Sastry ARK. Red Data Book of Indian Plants. Vol. 3. Kolkata: Botanical Survey of India; 1990.
  29. 29. Nayar MP. Hotspots of Endemic Plants of India, Nepal and Bhutan. Palode: Tropical Botanic Garden and Research Institute; 1996.
  30. 30. Gopalan R, Henry AN. Endemic Plants of India: Endemics of Agasthiyamalai Hills. Dehradun: Bishen Singh Mahendra Pal Singh; 2000.
  31. 31. Angiosperm Phylogeny Group. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Bot J Linn Soc. 2016;181(1):1–20. https://doi.org/10.1111/boj.12385
  32. 32. Edwin-Wosu NL, Hezekiah EE. Floristic enumeration of Obite Community Protected Area: A window for IUCN exploration and recognition in parts of Etche, Rivers State, Nigeria. J Divers Stud. 2025;4(1):83–94. https://doi.org/10.51470/JOD.2025.4.1.83
  33. 33. Packialakshmi M, Divya MP, Baranidharan K, Parthiban KT, Geetha S, Ganesan KN, et al. Floristic composition and structural analysis of flora in Nilgiris Biosphere Reserve, Western Ghats of southern India. J Trop For Sci. 2023;35(3):270–82. https://doi.org/10.26525/jtfs2023.35.3.270
  34. 34. Kumar A, Mitra M, Adhikari BS, Rawat GS. Flora of Niti Valley: A cold arid region of Nanda Devi Biosphere Reserve, Western Himalaya. Check List. 2016;12(1):1–16. https://doi.org/10.15560/12.1.1824
  35. 35. Palni LMS, Rewal RS. Compendium on Indian Biosphere Reserves: Progression during two decades of conservation. New Delhi: MoEF & CC.
  36. 36. Das AK, Chandrakasan S. Floral diversity of the Great Nicobar Biosphere Reserve, Andaman and Nicobar Islands, India. In: Faunal Ecology and Conservation of the Great Nicobar Biosphere Reserve. Springer Nature. p. 41–76. https://doi.org/10.1007/978-981-19-5158-9_2
  37. 37. Yadav SK, Dash SS. Floral resources of the Sundarban Biosphere Reserve, West Bengal, India and its socio-ecological importance. J Plant Dev Sci. 2023;15(10):509–24.
  38. 38. Misra RK, Upadhay VP, Mohanty RC. Vegetation ecology of the Similipal Biosphere Reserve, Orissa, India. Appl Ecol Environ Res. 2008;6(2):89–99. https://doi.org/10.15666/aeer/0602_089099

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