© 2022 Antony T, et al. This is an open access article distributed under the terms of the Creative Commons Attribution License -NonCommercial-ShareAlike Unported License (http://creativecommons.org/licenses/by-nc-sa/3.0/). Revised morphology and barcoding of Strobilanthes andersonii Bedd. a critically endangered plant Tiny Antony 1 , Jomy Augustine 1 *, Linu Mathew 2 1 Department of Botany, St. Thomas College, Palai, Kottayam, Kerala, India. 2 School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India. ABSTRACT Strobilanthes is a genus of perennial flowering shrubs with about 400 species. Due to the infrequent flowering period and monocarpic nature the availability of reproductive parts – the primary requisites for species identification – is comparatively a rare chance. Hence, other methods, such as molecular techniques, are vital to differentiate Strobilanthes species in the vegetative stages. The establishment of DNA barcode database is a suitable method. The DNA barcode region ITS nuclear ribosomal DNA of Strobilanthes andersonii Bedd was sequenced. A revised morphology of S. andersonii Bedd is also prepared. A ML phylogram was constructed to evaluate the phylogenetic perspective of S. andersonii Bedd. 1. INTRODUCTION Strobilanthes (Family: Acanthaceae) is a South-East Asian wet tropical evergreen genus that exists in moist forests. This genus with 400 species is the second largest in the family Acanthaceae [1], and distributed along the South and Southeast Asia. It reached India after the Indian subcontinent merged Asian mainland through the continental drift. The original genetic stock of Strobilanthes was probably a single species, reached from Malaysian region to the Western Ghats [2]. In India, there are 146 species of Strobilanthes distributed in the wet non- deciduous forests of the Western Ghats and the Himalayas [3]. Fifty- nine species are reported from South India with maximum endemism in Peninsular India [4]. Beddome incompletely described the species Strobilanthes andersonii Bedd in 1864 [5]. Due to the long flowering periodicity, no further collections of this plant were made making the description of this plant incomplete and no further attempt was made on revising the morphology till now. Furthermore, since then, this species was considered extinct [4]. The massive flowering of this species was noticed in the shola forests of Eravikulam National Park in 2008 (2). Pendent flowering spikes with large green bracts were the distinguishing feature of this species. In the present study, the gregarious flowering of S. andersonii Bedd is noticed in 2018 in the same locality. Hence, the flowering periodicity of this endemic shrub is ascertained as 10 years. *Corresponding Author: Dr. Jomy Augustine, Department of Botany, St. Thomas College, Palai, Kottayam, Kerala, India. E-mail: jomyaugustine66 @ gmail.com The recent collection of this species in flowering stage from Eravikulam National Park became a rediscovery of this species. Even though there was previous plant exploration in the same area (Eravikulam NP), there were no report of its existence. It shows that even though the plant flowered according to its own reproductive cycle the botanists who explored this area could not collect it in flowering stage. Furthermore, there was a note on previous reports indicating the huge collection of Strobilanthes in vegetative parts [6,7]. This urges a new attempt to identify the species of Strobilanthes using the foliar characters. Augustine [2] has proposed a key based on the foliar characters of Strobilanthes. The revised morphology of this species based on the recent data is given in this paper. However, a more precise mechanism is the utilization of molecular techniques for identifying the vegetative stages. DNA Barcoding uses short DNA sequences from nuclear and organelle genomes for the identification of biological specimens [8]. The difference between inter and intra-specific genetic distances within a group of organisms is DNA Barcoding gap [9]. DNA Barcoding can resolve taxonomic and evolutionary problems related to identification [10-12]. In DNA Barcoding, the basic concept is to discriminate the species by the variation in the DNA sequences. In species like Strobilanthes, where long flowering periodicity exists, DNA Barcoding is a suitable method for identifying already described species and describing new species. Nuclear ribosomal DNA (nr DNA) contains 18S, 5.8S, and 26S ribosomal RNA subunit and different spacer DNA regions in between [13]. In the present study, molecular phylogenetic elucidation of S. andersonii Bedd and related species of Strobilanthes was done Journal of Applied Biology & Biotechnology Vol. X(XX), pp. 1-6, XXXX, 2022 Available online at http://www.jabonline.in ARTICLE INFO Article history: Received on: December 01, 2021 Accepted on: June 10, 2022 Available online: *** Key words: DNA barcode, Strobilanthes andersonii Bedd, ITS nr DNA. DOI: 10.7324/JABB.2022.100610