Henckelia collegii-sancti-thomasii (Gesneriaceae), a new synonym of narrow endemic species H. hookeri of Northeast India

Based on detailed study of type specimens, other herbarium specimens, field study and relevant literature, the recently described new species Henckelia collegii-sancti-thomasii A. Joe, D. Borah, Taram and Sandhya is treated here as a synonym of little known narrow endemic species H. hookeri (C. B. Clarke) D. J. Middleton & Mich. Moller of Northeast India. Detailed description, phenology, habitat, geographical distribution and coloured images of the species are provided. The conservation status, following IUCN recommendations, is also provided based on the study of literature, herbarium data and field observations.