Abstract

Henckelia davidwoodii (Gesneriaceae) is described here as a new species based on collections made from the Shi-Yomi district in the eastern Himalayan state of Arunachal Pradesh, India. This new species resembles H. lallanii Taram, D.Borah, Tag and R.Kr. Singh in its habit, infundibuliform corolla without flaps or flanges, and stamens with slightly geniculate filaments, but it can be differentiated by having 2-flowered cymes (versus solitary in H. lallanii), ovate bracts with undulate margins (versus narrowly ovate-lanceolate bracts with entire margins in H. lallanii), non-reflexed 5-veined calyx lobes (versus reflexed calyx lobes without veins in H. lallanii), and a cupular disc (versus tubular in H. lallanii). It also superficially resembles H. urticifolia (Buch.-Ham. ex D.Don) A.Dietr., however, it can be differentiated by its distinct sessile to sub-sessile bracts with undulate margins and a round to cordate base, often recurved at the base and overlapping to form a conical to cupulate structure, and stamens that are slightly geniculate (versus bracts with serrate margins and cuneate bases, never forming the aforementioned structures; stamens distinctly geniculate in H. urticifolia). A detailed taxonomic description is provided for this new species, accompanied by photographs and ecological information.

Keywords: Henckelia, Indian flora, Indian Himalayan Region (IHR), northeast India, taxonomy