A new species of Henckelia (Gesneriaceae) from Arunachal Pradesh, India

Henckelia pathakii G. Krishna & Lakshmin. sp. nov., is described and illustrated here from Upper Siang district of Arunachal Pradesh, India. It differs from its closely related species H. adenocalyx and H. grandifolia in having cupular bracts (vs. free and slightly connate at base) and glabrous (vs. densely hairy or sparsely pubescent), eglandular calyx. As it is narrowly confined to Upper Siang district of Arunachal Pradesh in a small population comprising about 20 individuals in a single location. The threat status of this new species is provisionally assessed here as “Critically Endangered” following the IUCN Red List Categories and Criteria version 3.1 (2012).