Rediscovery of the monotypic Indianthus virgatus (Marantaceae) in Sri Lanka after 170 years: a conservation priority

Monotypic taxa, often defined by unique evolutionary histories, disjunct distributions, and narrow ecological niches, are of exceptional conservation importance. Here, we document the rediscovery of Indianthus virgatus (Marantaceae), a Critically Endangered monotypic species, in Sri Lanka after 170 years. Endemic to the Western Ghats–Sri Lanka biodiversity hotspot, the species was presumed possibly extinct in the wild in Sri Lanka, with the last known collection made by G.H.K. Thwaites in 1855. During targeted surveys conducted over 2 years, we located a wild population of I. virgatus along the Sitawaka Ganga River in a lowland evergreen forest fragment in Sabaragamuwa Province. Morphological analyses confirmed the species’ identity and revealed hitherto undocumented characteristics, including the presence of 1–3 seeds per fruit. This rediscovery after 170 years highlights the importance of targeted field surveys and the urgent need to conserve this Critically Endangered species under the national biodiversity conservation framework.