Humboldtia Vahl - An under-utilised, under-researched, and vulnerable tree genus endemic to the Western Ghats-Sri Lanka biodiversity hotspot.

•Humboldtia, is a scientifically valuable yet underexplored endemic genus from the Western Ghats - Sri Lanka Biodiversity hotspot.•Comprising just eight species, all of which are under threat of extinction, the genus is one of the evolutionarily unique plant lineages within the region's flora.•The genus shows ecological adaptations, such as domatia-mediated ant-plant symbiosis and cauliflorous flowering, which are important in its natural habitat.•Humboldtia is an exceptional model for investigating speciation dynamics, biogeographical diversification, and ecological specialisation in tropical forest ecosystems.•However, the genus remains poorly studied and inadequately protected, calling for increased attention in both research and conservation efforts.