Research Paper

Ophiorrhiza shidiensis & Ophiorrhiza pemae (Rubiaceae): Two new species from Arunachal Pradesh, India

Krishna Chowlu, Renthlei Lalnunfeli, Vinay Kumar Sahani

Published on: 23 October 2026

Page: 753 - 763

DOI: 10.6165/tai.2026.71.753

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    Abstract

    Two new species of Ophiorrhiza (Rubiaceae), Ophiorrhiza shidiensis Sahani, Chowlu & Lalnunfeli and Ophiorrhiza pemae Chowlu, Lalnunfeli & Sahani, are described from Changlang, Arunachal Pradesh, India. Detailed morphological descriptions, notes on their distribution and habitat, colour plates, provisional IUCN conservation assessments and comparisons with allied species are provided. Ophiorrhiza shidiensis is morphologically similar to Ophiorrhiza wallichii, but can be distinguished by its larger habit, variation in leaf lamina size, abaxially pale green leaves, presence of both axillary and terminal inflorescences, longer peduncles and pedicels, a pink corolla, and a vesicular stigma. Ophiorrhiza pemae is closely allied to O. himadrica, but can be distinguished by its taller habit, longer pilose-villous petioles, larger leaf blades with cuneate to rounded base, undulate margins and acute to attenuate apex, pale green abaxial surface, larger ovate bifid stipules, longer inflorescence in simple cymes, longer peduncles, ensiform to falcate bracts, light pink to purplish corolla, and micropunctate stigma.

    Keyword: Indo-Burma, new taxa, Ophiorrhiza, Ophiorrhiza himadrica, Ophiorrhiza wallichii, taxonomy

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