Taxonomy and threat assessment of Lagotis kunawurensis Rupr. (Plantaginaceae), an endemic medicinal plant species of the Himalaya, India

help during the course of the present study. Abstract: Lagotis kunawurensis Rupr. (Plantaginaceae), a rare plant species endemic to the Himalaya, is reported here after a gap of 50 years from Ladakh. This species has often been taxonomically misidentified and confused with Picrorhiza kurroa, an important medicinal plant of the Himalaya. The present study clarifies the taxonomy of L. kunawurensis by providing description and photo illustrations of diagnostic characters which will aid its proper field identification. Furthermore, the threat assessment of L. kunawurensis using the IUCN Red List of Threatened Species has been conducted based on the available occurrence records, and the species currently falls under the ‘Near Threatened’ category. This species is used for medicinal purposes by locals in the study area. As the species is simultaneously experiencing various kinds of threats and the known distribution range is relatively smaller, it is right time to develop conservation strategies for the sustainable utilization of this endemic medicinal plant species of the Himalaya.

ISSN 0974-7907 (Online); ISSN 0974-7893 (Print)  (Isbell et al. 2011). However, in recent times, plants are subjected to various threats such as habitat loss, overexploitation, pollution, illicit trade (Tali et al. 2014;Ganie et al. 2019), and increasing stresses associated with climate change (Urban 2015;Hamid et al. 2020). These anthropogenic pressures on plant diversity are predicted to push Earth beyond the tipping points (Steffen et al. 2015;Bachman et al. 2017). In response to such grave concerns, the Target 2 of Convention on Biological Diversity (CBD) has called for assessment of threat status at regional, national, and global level to identify plant species which need immediate conservation. Empirical evaluation of threat status of biodiversity has emerged as an area of immediate research focus (Agnihotri et al. 2107;Tali et al. 2018;Ganie et al. 2019). Designation of current threat status of a species is crucial in assessing the risk of extinction, development of conservation policy, and drawing public attention towards these species, as well as their declining habitats (Burton 2003;Tali et al. 2018;Ganie et al. 2019 In an era of biodiversity crisis, the correct taxonomic identification and scientific information on the occurrence and population status of endemic species is urgently needed to undertake threat assessment, and thereafter develop appropriate conservation strategies (Chitale et al. 2104;Tali et al. 2018;Khuroo et al. 2020). In the backdrop of L. kunawurensis being a narrow endemic species, the present study aimed to resolve its taxonomic confusion and also for the first time undertake an empirical assessment of its threat status across the Himalaya based on IUCN Red List criteria (IUCN 2012).

Study area
The Himalaya, covering an area of about 329,109.22 km 2 , is located between 25.065-35.082 °N & 73.013-97.041 °E, along the northern boundary of India (Chitale et al. 2014). The climate is sub-alpine-temperate in western Himalaya, while it is sub-tropical to temperate in eastern Himalaya; whereas annual temperature and precipitation is on average 5 °C and 1,200 mm in western Himalaya, it is 10 °C and 3,500 mm in eastern Himalaya, respectively. The wide elevation gradient in the Himalaya ranging from 500-8,800 m results in a variety of ecosystems within short distances, from alluvial grasslands and subtropical broadleaf forests along the foothills to temperate broadleaf forests in the mid-hills, mixed conifer and conifer forests in the higher hills, and alpine meadows above the treeline (Chitale et al. 2014).
The Trans-Himalayan region of Ladakh, the collection site of the present study, is located at the northwestern boundary of India between 21.095-37.083 °N & 72.066-78.041 °E. This region possesses a wide altitudinal gradient, land with diverse geological formations, resulting in the rich diversity of alpine and cold-desert flora (Nüsser & Dickorè 2002). The collection site namely, Sapi La is located in district Kargil of Ladakh at an altitude of 4,375 m, at 34.036 °N & 76.019 °E, and situated about 70 km towards the southwestern side of Kargil township.

Taxonomy
Standard herbarium methods (Bridson & Forman 1992) were used during collection, processing and preparation of the herbarium specimens. Voucher specimens have been deposited at the University of Kashmir Herbarium (KASH). Besides, an ethno-botanical survey was conducted in the study area to document the traditional use of this plant species. The survey usually started with the interview of elderly and experienced

Record of operative threats
The operative threats (both direct and indirect) to plant species and their habitats were assessed during different seasons of the year at regular intervals of time following Ganie et al. (2019).

Threat assessment
Occurrence records for Lagotis kunawurensis were obtained from the Global Biodiversity Information Facility database (GBIF 2018) using the 'gbif' function from the 'dismo' package (https://CRAN.R-project.org/ package=dismo) (Hijmans et al. 2017) and supplemented with the occurrence records from India Biodiversity Portal (IBP 2018), herbarium records (BSD, KASH) and field surveys.
Adopting the IUCN Red List Categories and Criteria, version 3.1 (IUCN 2012), we assessed the current threat status of the species based on the Criterion B; it takes into account the geographic range size as well as evidence of diminishing or fragmenting populations (Gaston & Fuller 2009;Cosiaux et al. 2018). The Criterion B is appropriate for assigning conservation status even when data is scarce and the geographic distribution of a species is known from only a few georeferenced herbarium records (Cosiaux et al. 2018). We used the ConR package (https:// CRAN.R-project.org/package=ConR) (Dauby et al. 2017) implemented in R software (https://www.R-project.org/; R Core Team 2018) to calculate extent of occurrence (EOO) and area of occupancy (AOO) based on the occurrence records of the species. EOO was calculated by constructing a minimum convex polygon around all the known occurrences while AOO was estimated as the sum of occupied cells after superimposing the grid with cells of desired size (Dauby et al. 2017;Cosiaux et al. 2018;Lughadha et al. 2018). During the present study, the minimum AOO was estimated based on a standard grid cell of size 2 x 2 km (IUCN 2017). In addition, we also calculated the number of 'locations', as defined by IUCN (2017), with respect to the various types of threats, so that a single 'location' may involve more than one adjacent sub-populations.  Brit. Ind. 5, 569, 1885 Plant herbaceous up to 23 cm tall; roots many, fibrous; basal leaves obovate-oblanceolate, with cuneate leaf base, dentate-denticulate margin and acuterounded leaf apex, 6-8 cm long and 1.5-2.2 cm broad, petiolate, petiole creamy with reddish tinge, 6-8 cm in length; stem leaves ovate, sessile, 2-3 cm long and 1-1.5 cm broad; inflorescence spike, flowers pale mauve or blue, numerous; calyx spathe-like; corolla tube slender, zygomorphic, bracts numerous, overlapping; stamens 2, filament as long as corolla or shorter; anthers reniform, black in colour; ovary 2 locular, superior; stigma capitate, bilobed (Image 1). Identification aid: In western Himalaya, there is a confusion regarding the identification between Lagotis kunawurensis and Picrorhiza kurroa (https:// sites.google.com/site/efloraofindia/species/mz/p/ plantaginaceae/lagotis/lagotiskunawurensis), therefore the comparison of the diagnostic characters between these two species is provided to facilitate their correct taxonomic identification (Table 1).

Taxonomic description
Flowering period: July-August. Ecological note: The species grows in the cold desert alpine areas which experience high speed winds and also prone to landslides. Also, the species is over-exploited for local use by herbal healers and whole plant along with roots is extracted. During the present study, the species was recorded only at one site (i.e., Sapi La) in the  (Figure 1).

Ethno-medicinal uses
The plant species, in particular roots, are used against abdomen cramps, inflammation, and brown phlegm. The plant is also used as liver tonic and to treat different types of fevers in the collection site of the present study.

Threat status
Empirical evaluation of the threat status revealed that the extent of occurrence (EOO) and area of occupancy (AOO) for L. kunawurensis is 2,78,896 km 2 and 88 km 2 respectively (Figure 1). Furthermore, the species is recorded from 24 unique localities, representing a total of 19 sub-populations from 20 different locations (sensu IUCN 2012) which are more than 10 locations that represent the upper most limits for the 'Vulnerable' (VU) category under sub-criterion 'a'. Therefore, L. kunawurensis is assigned under IUCN category of Near Threatened (NT) according to criterion B. Stewart (1972), Lagotis kunawurensis has not been reported from the Ladakh region (Kachroo et al. 1977;Polunin & Stainton, 1984;Klimeš & Dickoré, 2006;Behera et al. 2014), therefore the authenticity of its presence in this region was doubtful. However, the present study clearly demonstrates distribution of L. kunawurensis in the region. The species has been confused with similar-looking Picrorhiza kurroa, another important medicinal plant that grows in Ladakh. A detailed taxonomic description and photo illustrations of diagnostic characters, as worked out in the present study, will facilitate its easier field identification, which is crucial for its conservation and sustainable use.

After
The present study has revealed that L. kunawurensis is currently Near Threatened (NT). Being narrow endemic to the Himalaya, rare distribution at high altitudes and smaller population size in the region makes the species highly vulnerable to contemporary land-use and climate changes (Rana et al. 2017). Ladakh region is recently experiencing climate change, which can impact both floral and faunal diversity of the region (Barrett & Bosek 2018). As L. kunawurensis is a narrow endemic species, thus considered more prone to extinction due to changing climate (Muthumperumal et al. 2020). In Ladakh, the species is mostly extracted by 'Amchis' (local herbal healers) for preparation of traditional medicine.

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in physico-chemical properties of the soil, which in turn can render the natural habitat of endemic species unfavorable, and lead to their population decline (Tali et al. 2014;Ganie et al. 2019). If these threats continue to operate unchecked, the species is highly susceptible to become threatened in near future. To focus conservation action at a regional scale, it becomes necessary to prioritize these species in their natural distributional range (Nori et al. 2016). Therefore, in an era of rapid land-use change and climate crisis, the results from present study have wide relevance in devising successful conservation strategies for this endemic species in high-altitude habitats of the Himalaya. Looking ahead, the present study can serve as an early warning for undertaking urgent efforts to conserve this important endemic medicinal plant species.

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