Lasianthus yalaensis Napiroon, Duangjai & Poopath is described and illustrated with notes on its conservation, and phylogenetic placement. The new species is morphologically similar to L. pilosus from which it differs in: its strigose branches (vs pilose), leaf blade 5-8 x 2-2.5 cm (vs 10-12.5 cm), 7-8 pairs of nerves (vs 9-15), stipules 5-7 nun long (vs