Endemism and conservation status of podostemaceae in northeastern Thailand

Abstract

Podostemaceae, a family of aquatic flowering plant restricted to river rapids and waterfalls are widely reported to be the high incidence of endemism and in need for conservation. The present study analyses endemism and conservation status of the Podostemaceae in northeastern floristic region Thailand using past and current taxonomic records, personal field collections, geographic ranges, IUCN assessment, and a combination of river number in which a species occurs. The plants grown in one river and two rivers are considered as narrow endemic species. Among the six genera and 22 species recognized, two genera are endemic, eighteen species are endemic to Thailand, eleven species of the 18 are narrowly distributed and confined in northeastern floristic region, and the other 4 species are not endemic. Considering the conservation status, two species are classified as Critically Endangered distributed in a single river, ten species as Vulnerable distributed in 1-2 rivers, six species as Near Threatened, two species as Least Concern, and two species as Data Deficient. Loei province is the most species-rich area in Thailand with 12 species, five of them are restricted in Loei.