not-yet-known not-yet-known not-yet-known unknown A new species of Gesneriaceae, Lysionotus calcicolus Phonep., Soulad. & Souvann., is described and illustrated based on morphological and molecular evidence. This species is distributed in limestone karsts in Luangprabang, Vientiane, and Khammouane provinces, from northern to central Laos. The new species can be distinguished from the hitherto known species in the genus by its deciduous shrubby habit, up to 2 m tall, and 4-angled stems which are considered to be an adaptation to the severe environment in limestone karst and cliffs. The information on its distribution, ecology, phenology, vernacular name, and provision of conservation status are provided.