Medicinal Uses of Wild Edible Plants by the Wancho Tribe in Longding District of Arunachal Pradesh

Jayanta Gogoi¹, Madhubala Sharma¹*

¹Department of Forestry, North Eastern Regional Institute of Science and Technology, Nirjuli, Itanagar, Arunachal Pradesh 791109, India.

*Email: [email protected]

ABSTRACT

Wancho tribe is one of the major tribes of Arunachal Pradesh and uses various plants to cure different diseases traditionally. The main aim of the study was to document the wild edible plants used for medicinal purposes. The field survey for data collection was carried out from July 2019 to July 2021 in 23 Wancho tribe-dominated villages of the Longding district of Arunachal Pradesh through questionnaires and interviews. A total of 51 plant species belonging to 40 genera and 36 families were recorded. Clusiaceae was the most dominant family with 5 species.   Use value (UV) was observed highest in Clerodendrum glandulosum Lindl., Colocasia esculenta (L.) Schott., Diplazium esculentum (Retz.) Sw., Paederia foetida L., Solanum indicum L.and Houttuynia cordata Thunb. The highest ICF was observed in disease categories, namely bone fracture, liver problem, malnutrition, gynecology, antidote, cold & cough problem. The highest Fidelity level (FL) was found in Erythrina stricta Roxb. (100%), Clerodendrum glandulosum Lindl. (100%) and Euphorbia neriifolia L. (100%). The current study revealed the importance of wild edible plants in treating various diseases for day to day life of the Wancho tribe.

Key words: Conservation, Ethnomedicine, Practices, Traditional knowledge, Wancho

INTRODUCTION

Plants that cure different diseases are called medicinal plants. All over the world, different tribes have their medicinal system [1]. About 80% of the world's population depends on traditional medicines for their primary health care [2]. Many of rural communities still rely on traditional medicine. Therefore, studying ethnomedicinal plants is recognized as an important field of research nowadays.

The northeast region is rich in both flora and fauna. It falls under Indo-Burma Global Biodiversity Hotspots [3]. Arunachal Pradesh is one of the wealthiest states of NE India and lies between from 26.28° N to 29.30°N latitude and 91.20° E to 97.30° E longitude. It covers an area of 83,743 sq. km. and shares its borders with Assam and Nagaland; international borders with Bhutan, China, and Myanmar. This state is ethnically diverse and has a home total of 26 major tribes and more than 100 sub-tribes. Major tribes are Adi, Nyishi, Monpa, Apatani, Mishmi, Nocte, Wancho, etc. [4]. The people of the Wancho tribe mainly inhabit in Longding district of Arunachal Pradesh, India. Culturally they are Naga and ethnically related to the Nocte tribe of Arunachal Pradesh and the Konyak tribe of Nagaland. The language of the Wancho tribe belongs to the Tibeto – Burman family. The religion of the Wancho tribe is mainly Christian, followed by Hindu, and some of them still believe in Animist. The Animist Wancho believes in the existence of two powerful deities, namely Rang and Baurang. 

Nutrients, medicine, fodder, and spices are derived from wild edible plants. People prefer to use these plants due to their freshness, aromatic taste, pollution-free growing environment, and excellent vitality [5]. Similarly, people in rural areas not only consume wild plants as a source of food but also as a medicine [6]. There is limited ethnobotanical information on the uses of plants by the Wancho tribe. The available literature reveals the studies on the fishing practices of the Tirap district [7], botanical resources used in the traditional wood curving industry [8], crop diversity in traditional Jhum cultivated land practices [4], festivals and ceremonial of Wancho society of Assam [9] and edible insects used as a food by Tangsa and Wancho tribes of Changlang district [10]. A preliminary investigation on ethnomedicinal plants and the anti-proliferating activity of some toxic and medicinal plants were conducted by Wangjen et al. and Wangpan et al. [11, 12]. Since there is no report on the use of wild edible plants by this tribe, therefore, the present study was an attempt to document wild edible plants used for medicinal purposes

MATERIALS AND METHODS

Study area

The study was conducted in the Longding district of Arunachal Pradesh which is geographically located at 26° 51' 51.84" N and 95° 19' 36.3" E. The district shares its boundary with Myanmar towards south and south-east, Nagaland and Assam state to west and north, and Tirap District of Arunachal Pradesh to north and east. The total area of this district is roughly 1200 square kilometers. The district consists of six circles, namely Longding, Kanubari, Pongchau, Wakka, Pumao, and Lawnu (Figure 1). The population of the Longding district is around 47,788 [9] and is mainly inhabited by the Wancho tribe.

Field visits were conducted in 23 villages of Longding district for two years (2019 – 2021). The respondents were selected for the interview according to the stratified random sampling method. The personal interviews and group discussions among villagers were carried out with the help of a semi-structured questionnaire to obtain detailed information on wild edible plants used for medicinal purposes. A total of 392 respondents were interviewed for data collection. The documented plant species were identified with the help of taxonomists and available literature.

The ethnobotanical indices

The use-value (UV), Fidelity level (FL), and informant consensus factor (ICF) were determined by using the formulae given below, as suggested by Phillips et al. [13], Friedman et al. [14] and Trotter et al., Heinrich et al. [15, 16].

Where, U is the sum of the total number of use citations by all informants for a given species, and N is the total number of informants.

Where Np is the number of informants that reported the use of a plant species to treat a particular disease, and N is the number of informants that used the plant as a medicine to treat any given disease.

Where Nur refers to the number of use reports for a particular use category, and Nt refers to the number of taxa used for a particular use category by all informants.

Results and discussion

Arunachal Pradesh is a homeland of a large number of precious medicinal plants. All tribal communities of Arunachal Pradesh use ethnomedicines for their health care practices. They use different parts of the plants to cure illnesses and diseases. In the present study, a total of 131 wild edible plants were recorded, of which 51 plant species were recorded for curing different diseases by the Wancho tribe and were listed in alphabetical order in Table 1. The listed species belonged to 40 genera and 36 families. The highest number of plants were from the family Clusiaceae (5), followed by Asteraceae (4), Araceae (3), Lauraceae (3), Acanthaceae (2), Lamiaceae (2), Apiaceae (2), Euphorbiaceae (2), etc. Habit-wise, trees were most dominant (39.21%), followed by herbs (33.33%), shrubs (21.56%), and climbers (5.88%) (Figure 2). Traditional healers and other life forms used trees because the trees were commonly available around their surroundings and easily accessible to collect their different parts. In this study, it was found that the most common plant parts used were leaves (47.36%) followed by fruit/seed (24.56%), the whole plant (8.77%), roots (7.01%), bark, stem, and flowers (3.5% each) as given in Figure 3.   Due to the potential existence of active chemical compounds, leaves are widely used for the preparation of herbal medicines as compared to other parts [17]. In the present study, digestive and stomach-related disorders were the most common ailments, followed by dysentery and blood clotting. The UV value ranged from 0.114 to 1. Based on UV (Table 1), the most commonly used ethnomedicinal plant species were Clerodendrum glandulosum Lindl. (1), Colocasia esculenta (L.) Schott. (1), Diplazium esculentum (Retz.) Sw. (1), Paederia foetida L. (1), Solanum indicum L. (1), and Houttuynia cordata Thunb. (1) These species are consumed daily as vegetables by local people in one or another forms to treat multiple diseases. The lowest UV was observed in Euphorbia neriifolia L. (0.114), which may be due to its use to treat a single disease, i.e., bone fracture.

Table 1. Documentation of wild edible plants used as medicine by the Wancho tribe

A total of 14 aliment groups were categorized as given in Table 2. The ICF ranged from 0.951 to 1. The highest ICF was observed for bone fracture, liver problems, malnutrition, gynecological problems, antidote, and cold & cough problems because only one plant was reported to cure each disease group (Table 2). ICF value ranged from 0.95 (digestive disorder) to 1(antidote, blood pressure, bone fracture, liver problem, etc.). The lowest value of ICF in digestive problems may be due to the use of more plant species than other disease categories. It is observed that people of this tribe used to consume fruits of Terminalia chebula Retz., Spondias pinnata (L. f.) Kurz, Garcinia cowa Roxb. ex Choisy and leaves of Houttuynia cordata Thunb., Paederia foetida L., Chromolaena odorata (L.) R.M. King & H. Rob., Begonia roxburghi A. DC., as vegetables either raw or in the boiled form in their daily meals to cure digestive problems. The Fidelity level (FL) of the 14 most preferred plant species in Table 2 showed the highest FL value (100%) in Clerodendrum glandulosum Lindl. and Erythrina stricta Roxb is ubiquitous in the study area and highly effective for treating blood pressure and antidote, respectively. The lowest FL level was observed in Citrus maxima (Burm.) Merr. (8.67%) as only a few informants reported the use of this plant to cure the gynecological problem.

Table 2. Informant's Consensus Factor (ICF) of most cited species against major disease categories along with Fidelity Level (FL)

Conclusion

The present study reveals the information on traditional knowledge of wild edible plants as medicines by the Wancho people, which shows that the traditional treatment system is still prevalent in this tribe. The conservation of these plant species should be encouraged for their adequate supply of food resources. There is an urgent need to conduct pharmacological studies on these plants, which may lead to the development of new medicines.

ACKNOWLEDGMENTS : We are thankful to all the respondents of the Wancho tribe for providing valuable information on the medicinal uses of wild edible plants.

CONFLICT OF INTEREST : None

FINANCIAL SUPPORT : None

ETHICS STATEMENT : Permission was obtained from the village Head or King of the Wancho tribe to conduct the study.