Human health depends on the quality of the environment in which they live. The interrelationships between society and nature, and the importance of environmental health to human health depend on biodiversity which have direct impact on human-well being as well [1] . Human population is growing at an alarming rate in the developing countries and only ~30 plant species are used to meet 95% of the world’s food requirements, which are considered as the “major crops” [2] [3] . Millions of people in the developing countries do not have enough food to meet their daily requirement, further the diet is deficient in one or more nutrient [4] and same is true to India, world second largest in human population in this earth [5] . Mankind depends on a very limited number of crop plants to meet the needs of staple diets [6] . Increasing reliance on these major food crops leads to shrinking of the food basket which mankind has been relying upon for generations [7] and the need to feed hundreds and thousands of mouth has led to starvation in many developing countries [8] . The gap between the human population and the quantity of the food supply has already become a global threat and an international issue [9] and therefore, to bridge the gap efforts are being made to identify and evaluate underutilized food sources [10] . Since time immemorial, man lived by hunting and gathering and has been using wild plants as food source [11] .

Biodiversity is the very basis of human survival and economic well being that constitutes the resources upon which families, communities, nations and future generations depend [12] . The status and characteristics of biodiversity prevalent in a country/state/region is dependent on the land (soil, topography), climate and people (their habitats and population density) inhabiting the region [13] . Biodiversity and bioresources are key in securing different fundamental human needs [14] [15] [16] . India is one of the 17 mega-biodiversity rich regions and the North-Eastern part of the country harbours rich and unique biodiversity. India has rich concentration of 500 tribal communities, who have close association with the forest and its resources since time immemorial. The tribal communities also use locally available medicinal plants to meet their daily healthcare needs which have become a recognized tool in search for new sources of drugs and nutraceuticals, these medicinal plant offers an economically inevitable alternative to expensive medicines [17] . Forest plays a large indispensable role in improving the food security and livelihood of the tribal society [18] . Millions of people in many developing countries depend on forest resources including wild edible plants to meet their food needs especially in periods of food crisis [4] [19] . Therefore, forest resources reduce the vulnerability of local communities to food insecurity and provide a buffer in times of food shortage [19] [20] [21] . The wild edible plants provide staple food for indigenous people, serve as complementary food for non-indigenous people and offer an alternative source of cash income [22] [23] [24] and they have substantial potential for the development of new crops through domestication and provide a genetic resource pool for hybridization and selection [25] [26] [27] .

The North-Eastern region being one of the hot-spots of biodiversity is known for its richness in ethnic diversity and traditional culture [28] . Nagaland state is part of the Indo-Burma biodiversity hot-spot which have a diverse flora and fauna. The state is inhibited mostly by the tribal people called the Naga tribes. Naga are Mongolian race with racial and socio-cultural affinities with the inhabitants of Southeast Asian countries forming one of the largest tribal communities in North-Eastern India [29] [30] . Though the Naga society have been greatly influenced by modern cultures, yet traditional cultures are practice even today and they still depend widely on forest resources for food, shelter, and medicines. Forest resources especially wild edible plants plays a major role in supplementing the staple foods in many tribal areas [31] [32] [33] , however many of the wild edible plants are unknown to people outside the state and remains insufficiently exploited, despite their nutritional values, thus becoming underutilized crops at the global level.

Jaenicke Höschle-Zeledon [34] defined Underutilized crops as “those species which are under exploited for contributing to food security (nutritional/medicinal), income generation and environmental services”. They are also referred as “Neglected and Underutilized species”/“Orphan crops”/“Minor crops” [35] [36] . These plants as locally abundant but globally rare, lack of scientific knowledge, has a limited current use relative to their economic potential. They are often presented as “New crops” for the fact that commercial companies/researchers are only recently working on them [37] . Replacing traditional foods by “modern feeding habits” has resulted in the loss of genetic diversity in traditional food species and a decline in cultural diversity [38] . The vast store of information on indigenous knowledge, practices and technologies is being eroded as a result of rapid urbanization, over-exploitation of resources, unscientific land use, change of lifestyles and behavior [39] . As reported by Blanco [40] , regarding issues of traditional culture the process of oral transmission has broken down and most traditional knowledge can only be found in the memory of the elderly and is gradually fading as these repositories of ancestral knowledge received from parents and grandparents succumb to age. The loss of indigenous knowledge has also been recognized as one of the general factors affecting biological diversity [41] . There is an urgent need for exploration on traditional knowledge of underutilized plant uses, development of database, strategy for conservation through sustainable use and management of the resources and search for new potential plant sources as drugs and food [31] and to support biodiversity conservation programs [27] . Present study has been undertaken to survey and document the Underutilized Edible Plants (UEP’s) from three districts (Kohima, Phek and Tuensang), Nagaland, India.

From the present investigation, a total of 142 UEP’s were collected during the survey which consists of 126 plants species and 16 wild edible mushrooms or macrofungus species. Table 1 showed the different types UEP’s categorized

Note: Ang: Angami tribe. NA: Not available.

according to types of plants and their parts used collected during the period 2012-2016 with their scientific name, family, common Name, vernacular Name, accession number. The collected 126 UEP’s belonging to 58 family and 95 genera, of which 49 family and 84 genera belongs to dicotyledones (Acantheceae, Actinidaceae, Adoxaceae, Amarantheceae, Anacardiaceae, Apiaceae, Araliaceae, Asteraceae, Athyriaceae, Begoniaceae, Berberidaceae, Boraginaceae, Brassicaceae, Capparaceae, Clusaceae, Combretaceae, Cornaceae, Cucurbitaceae, Ebenaceae, Elaeagnaceae, Elaeocarpeceae, Fabaceae, Fagaceae, Juglandaceae, Lamiaceae, Lauraceae, Malvaceae, Melastomataceae, Moraceae, Myricaceae, Myrtaceae, Olaceae, Oxalidaceae, Passifloraceae, Phyllantheceae, Plantaginaceae, Polygonaceae, Primulaceae, Rhamnaceae, Rhizophoraceae, Rosaceae, Rubeaceae, Rutaceae, Sapindaceae, Saururaeceae, Solanaceae, Ulmaceae, Urticaceae, Vitaceae) and 9 family with 19 genera belonging to monocotyledones (Amaryllidaceae, Asparagaceae, Araceae, Arecaceae, Costaceae, Dioscoreaceae, Musaceae, Poaceae, Zingiberaceae). Among all the 58 families, Rosaceae and Urticaceae were found to be the dominant family amongst dicotyledones with 8 generas each which was followed by Moraceae with 7 generas and Asteraceae and Polygonaceae with 6 generas each. Poaceae was found to be dominant family amongst monocotyledones with 5 generas followed by Araceae with 4 generas, Zingiberaceae with 3 generas and Musaceae and Arecaceae with 2 genera.

From the collected 126 underutilized edible plant species, 3 were cereal crops (Coix-lacryma jobi, Setaria italica and Sorghum bicolor), 50 leafy vegetables where the young shoots and leaves or the whole plant part is taken as vegetable, 62 fruits and nuts where fruits are eaten young or mature, ripe or unripe and nuts are eaten raw or roasted, 8 plants (Amomum dealbatum, Bauhinia variegata, B. purpurea, Curcuma angustifolia, Chimonobambusa callosa, Musa sikkimensis, M. thomsonii, Dendrocalamus giganteus) where either stem, flower or inflorescence are taken as vegetable and 3 plants (Allium tuberosum, Dioscorea bulbifera, Cinnamomum verum) where either root, tuber, rhizome or bulb are eaten.

Nagaland is blessed with rich floristic diversity and is one of the 25 hot spots of the world with respect to its biodiversity. The forest provides all the essential necessities such as food, fuel, wood, fodder, medicine, timber, raw material, shelter and protection and also forest related activities such as gathering forest resources for trading is an important source of livelihood income for the tribal and indigenous inhabitants [42] . The collected underutilized edible plants from the three districts of Nagaland consist of 3 cereal crops which are mostly cultivated by the farmers of Kohima, Phek and Tuensang district. These crops were either taken in place of rice or along with rice by the locals. Cereal crops are economically important to many local people as they provide means of food security as well as source of income generation through the cultivation and marketing of these crops. In the local market of these districts a cup or a packet which is approximately 500 grams could fetch around Rs. 50-100 INR. But during the study investigation it was found that with the course of time, the cultivation of these crops was reduced though the demand of the crops were high, one of the reason was damages caused by the infestation of birds in the case of Setaria italica (Foxtail millet) and Sorghum bicolor (Great millet) as their seeds are small making it easy target for the birds to eat them and Coix-lacryma jobi (Job’s tears) by squirrels. It becomes difficult for the farmers to keep away these pests from damaging the crops and thus maintenance becomes difficult ultimately resulting in lesser or reduction in the production of these Fifty UEP species are consumed in the form of young shoots and leaves or the whole plant when tender. Some of the wild leafy vegetables including Antidesma bunius, Clerodendrum glandulosum, Houttuynia cordata, Gynura bicolor, Polygonum chinense, Polygonum molle, Trichodesma khasianum, Gynura nepalensis were also cultivated in home gardens. Many of these leafy vegetables were also found selling in the local market costing around Rs. 20 - 30 INR per bunch (200 - 250 grams).

Sixty two fruits and nuts were documented in the present study, They are mostly consumed when ripe and mature while some of them are eaten when young including Trichosanthes dunniana, Canavalia gladiata Oxalis corniculata. Plant of Ficus auriculata, Elaeagnus latifolia, Docynia indica, Mahonia nepalensis, Myrica esculenta, Prunus nepalensis, Litsea cubeba, Phyllanthus emblica, Livistona jenkinsiana, Melastoma malabathricum, Caryota urens, Baccaurea ramiflora, Ardisia Crispa are collected from the wild and cultivated in the home gardens. Seeds of Castanopsis indica, Juglans regia and Hodgsonia macrocarpa are taken in the form of nuts). The fruits and nuts were sold in local market in fresh form, dried form or roasted or made into a local product which cost around Rs. 20 - 50 per 400 - 500 gm packet. Eight UEPs has edible stem, flower and inflorescence and 3 have edible root, tuber and bulb. Common UEPs found selling in the local markets are Amomum dealbatum, Curcuma angustifolis, Chimonobambusa callosa, Cinnamomum verum, Dioscorea bulbifera, Dendrocalamus giganteus, Musa sikkimensis, and Musa thomsonii). Wild edible mushrooms have been consumed by mankind since time immemorial [43] . Besides having high nutrient content such as proteins, vitamins, minerals, fibers, trace elements and low/no calories and cholesterol [44] , mushrooms are also known to berich sources of various bioactive substances [45] [46] . In the present study, 16 wild edible mushrooms were collected from the three districts of Nagaland belonging to 11 families, with 5 families having 2 species each namely, 1) Lyophyllaceae [Termitomyces heimii Natarajan and Termitomyces microcarpus (Berk. & Broome) R. Heim], 2) Auriculareaceae [Auricularia auricula-judae (Bull.) Quél. and Auricularia polytricha (Mont.) Sacc.], 3) Polyporaceae [Laetiporus sulphureus (Bull.) Murr. and Lentinus squarrosulus Mont. Singer], 4) Russulaceae [Lactarius volemus (Fr.) Kuntze and Lactarius piperatus (L.) Pers], 5) Tricholomataceae [Melanoleuca grammopodia (Bull.) Fayod and Tricholoma imbricatum (Fr.) P. Kumm.], and remaining 6 families with 1 species each namely, 1) Hydnangiaceae [Laccaria tortilis (Bolton) Cooke], 2) Marassmiaceae [Lentinula edodes (Berk.) Pegler], 3) Pluerotaceae [Pleurotus pulmonarius (Fr.) Quél.], 4) Schizophyllaceae (Schizophyllum commune Fr.) and 5) Cantherellaceae [Cantharellus cibarius (Fr.)], 6) Agaricaceae [Termitomyces eurrhizus (Berk.) R. Heim]. It was observed that most of the local people love collecting the wild mushroom during mushroom seasons. There was no gender oriented when it comes to mushroom collection, both young and old, men and women equally participate. The collected mushroom are locally consumed, while some are marketed both in fresh and dried form, which cost around Rs. 50 - 100 INR (fresh) to even Rs. 200 INR (dried) per plates (200 - 300 gm) according to the season.

With each passing time, there is increase of population leading to more demand of food to feed hundreds and thousands of mouth and which has led to narrowing the world food basket, necessitate to promote crop/food diversification to meet the need of the hungers. The present study aims to collect and document UEPs of three district of Nagaland, in an effort to widen our knowledge on different types and uses of these plants. UEPs have the potential to provide food security that can sustain the future generation. The study will also help create awareness about the potential nutritional values of the UEPs among the consumers. Survey and documentation of UEPs from the remaining districts of Nagaland are urgently required. Most of the products (UEPs) sold in the local markets are collected from forest UEPs are in high demand because of its taste, medicinal properties etc. Sustainable collection and proper conservation strategies need to be workout to prevent depletion of natural population and lost of the natural habitat caused mainly by anthropogenic activities. Knowledge of the phytochemical and nutraceutical properties of these UEPs will help improve its marketability.

Authors are thankful to the local people of Kohima, Phek and Tuensang district for sharing their valuable knowledge to us and also rendering all their help during the survey in different districts. Authors are also thankful to the Department of Biotechnology, Ministry of Science and Technology, New Delhi, India for financial support for the present study through “Institutional Biotech Hub”. Facilities used from the UGC-SAP (DRS-III) programme are duly acknowledged.

The authors declare no conflicts of interest regarding the publication of this paper.

Deb, C.R., Khruomo, N. and Paul, A. (2019) Underutilized Edible Plants of Nagaland: A Survey and Documentation from Kohima, Phek and Tuensang District of Nagaland, India. American Journal of Plant Sciences, 10, 162-178. https://doi.org/10.4236/ajps.2019.101014