Agasthyamalai Biosphere Reserve: 3,261 Flowering Plant Species Documented

A new checklist by the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI) has documented 3,261 flowering plant species in the Agasthyamalai Biosphere Reserve (ABR).

About Agasthyamalai Biosphere Reserve

• The Agasthyamalai Biosphere Reserve extends across Kerala and Tamil Nadu in the southern Western Ghats.
• Its hill systems and vegetation form a biologically unique but ecologically fragile landscape.
• It is one of the four biosphere reserves in southern India.

Key Findings of the Study

• Researchers documented 3,261 species, 26 subspecies and 28 varieties.
• These belong to 1,139 genera and 190 plant families.
• Fabaceae is the most species-rich family with 349 taxa.
• It is followed by Rubiaceae (194), Poaceae (193) and Orchidaceae (168).

High Level of Endemism

• About 1,018 taxa, or 31.2% of the flora, are endemic to India.
• This includes 245 steno-endemic taxa, restricted to highly specialised and limited habitats.
• The high endemism reinforces Agasthyamalai’s importance as a major centre of angiosperm diversity and conservation.

Biogeographical Link with Sri Lanka

• The flora shows a strong biogeographical affinity with Sri Lanka, with the two regions sharing 347 taxa.
• This similarity may reflect historical land connections, shared Gondwanan origins and long-term climatic similarities.

Link with Tropical American Flora

• The study identified 102 taxa showing affinity with tropical American flora.
• This may be due to long-distance dispersal or naturalisation following human introduction.

Significance

• The checklist provides an updated scientific baseline for biodiversity monitoring, habitat protection and conservation planning.
• It strengthens the case for protecting the southern Western Ghats from habitat degradation and ecological fragmentation.