Research Paper

Ophiorrhiza himadrica & Ophiorrhiza bharat (Rubiaceae), two new species from Arunachal Pradesh, India

Madhusudhan Khanal, Nirjala Khanal, Shuvadip Sarkar, Santosh Kumar Rai, Devendra Kumar

Published on: 06 April 2026

Page: 325 - 334

DOI: 10.6165/tai.2026.71.325

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    Abstract

    Two new species of Ophiorrhiza (Rubiaceae), Ophiorrhiza himadrica M.Khanal, D.Kumar & S.Sarkar, and Ophiorrhiza bharat M.Khanal, D.Kumar & S.Sarkar, are described and illustrated from Arunachal Pradesh, India, situated within the Eastern Himalaya Biodiversity Hotspot. Ophiorrhiza himadrica was discovered in a temperate mixed forest near Menchuka and shows morphological affinity with O. medogensis H. Li, whereas O. bharat, found in a subtropical evergreen forest near Hone village, resembles O. ochroleuca Hook.f. to some extent. Despite their superficial similarities with allied taxa, both species can be readily distinguished by a unique combination of vegetative and floral characters. Detailed morphological descriptions, diagnostic comparisons with closely related species, colour photographic plates, notes on phenology and habitat, biogeographical discussion, ecological differentiation, and preliminary conservation assessments are provided to facilitate accurate identification and to support future taxonomic and ecological research in the region.

    Keyword: Heterostyly, Himalayan, Ophiorrhiza himadrica, Ophiorrhiza medogensis, Ophiorrhiza ochroleuca, Ophiorrhizeae

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