**1. Introduction**

The extinction of plant species resulting from human activities throughout the world has become a major concern [1]. Forest resources diminish as a result of deforestation, which has negative impact on agriculture, medicine and economic enterprises of man [1, 2]. Forest resources provide numerous goods and services to man such as food, medicine, wood, fiber and energy, they were taken for granted in the past because they were available almost everywhere but the situation has changed due to adverse effects of human activities [3, 4]. Food insecurity remains a major challenge in developing countries and insufficient nutrient intake causes severe malnutrition affecting the populace [5].

Worldwide, the problem of food security leads to calorie deficit of more than 700,000,000 underfed people [6]. The valuation of edible fruits and vegetables that are underutilized is one of the ways out of this impasse, a few examples of such extinct fruit and vegetable species with potential to address global undernourishment problems particularly those confronting the developing countries are *Plukenetia conophora, Saba senegalensis, Adansonia digitata* and *Ceiba pentandra*. They are potential sources of vitamins, minerals, antioxidants and phenols [7]. Indigenous plant species are outstanding plants due to their numerous benefits. Many of them are richer in protein and other nutrient contents [8]. They are good sources of macro and micronutrients for human consumption; many indigenous fruits and vegetables are characterized by a high nutritional value in comparison with global vegetables like tomato and cabbage [9]. Notably, many are potential sources of vitamins and macro and microelements with the ability to provide them to children and adult at levels higher than those recommended by the World Health Organization (WHO) [10]. Consumption of fruits and vegetables can improve health and prevent the risk of developing chronic diseases including cancer [11]. Consuming adequate quantity of food can be assured by utilizing nutrient-rich fruits and leafy vegetables accompanied with staple food. Generally, indigenous plant species are important as food, medicine and socio-economic value.

In spite of the numerous potentials of these indigenous crops, they have not been cultivated like other tropical plant species in Nigeria as a result of lack of adequate knowledge on their nutritional value, climatic requirement, fertilizer requirement and agronomic practices. Crop yield is to a large extent, associated with its fertilizer requirements, and maintaining the yield and quality of a newly introduced crop involves suitable crop management practices to improve soil productivity [12, 13]. Soil amendment could be done using organic or inorganic fertilizer and may be combined [14]. Therefore, investigating into food, nutritional, medicinal, climatic and fertilizer requirements of these indigenous crops can provide evidence-based information encouraging the cultivation of these wild species in order to remedy food insecurity, improve the diet of the people and prevent the crops from going into extinction. The information will also be useful to the food industries and pharmaceutical companies.
