The high diversity of wild edible plant species (Table 1) in Teso-Karamoja region demonstrates that people in and around forest reserves possess information about local vegetation that provides food. This is in tandem with the availability hypothesis  which asserts that people use plants that are more accessible or locally abundant. It ought to be noted that availability is often conceptualized as a physical distance from a home or community to the location where the plant grows in the wild but can also be considered in terms of seasonality, abundance, and price as well as access to markets, gardens, or natural areas where the plants are found . The number of species recorded in this study is comparable to the 114 edible plant species (57 families) reported in the Eastern Arc Mountains of Tanzania . However, it is also higher than the 77 species reported in Ethiopia , 72 species in Kenya , and 52 species reported in the Middle Agri Valley of Italy . This variance in the diversity of edible wild plant species has been attributed to disparities in culture and location . The Rubiaceae, Fabaceae, Anacardiaceae, Amaranthaceae, and Moraceae families are widely known to be among the largest and economically important sources of food and are widespread in the tropics .
The presence of exotic species namely Passiflora edulis Sims., Carica papaya L., Solanum lycopersicum L., Lantana camara L., Musa paradisiaca L., Psidium guajava L., and Amaranthis hybridus L. subsp. cruentus (L) Thell among the wild edible plants in this region is evidence for the diversification hypothesis . The incorporation of exotic plants in traditional diets enriches culture as opposed to being a sign of cultural erosion or environmental degradation. These exotics exist as weedy escapees, naturalized, or invasive species while some of them such as P. edulis, P. guajava, C. papaya, A. hybridis, M. paradisiaca, and S. lycopersicum can be purposively cultivated.
All the forest reserves investigated are woodlands, and this partly explains why the trees represent the majority of edible plant species (Fig. 4), they are not the most important sources of wild food (Fig. 5). This information is very useful in prioritizing wild plant species for domestication initiatives or in situ conservation and further investigation of their nutritional and mineral quality. Again, the number of species in each lifeform is dynamic and varies from one ecological niche to another. While herbs were the majority amongst the subsistence farming communities of Amuria district, Uganda , in Nhema Communal Area, Midlands Province, Zimbabwe, trees comprised the majority of edible species . These results conform to the plant use value hypothesis proposition that the usefulness of a plant for food, medicine, construction, technology, or trade in any community is directly related to its botanical family, lifeform, local abundance, and/or maximum size .
The fruits were considered the most important use category (Fig. 7) because they require no sophisticated means of preparation. The average number of wild edible plant species in Table 2 affirms the relative importance of the five use categories in Fig. 7. They are often eaten opportunistically as one is undertaking other core activities such as gardening, grazing, collecting firewood, fetching water, or hunting. Whereas opportunistic collection of wild edible plants was attributed to only women and children during firewood or water fetching , our findings reveal that even adult males engaged in hunting, livestock grazing, gardening, and collecting construction materials opportunistically forage wild edible plants. Generally, the fondness of an edible part is attributable to the ease of processing, nutritional value, and the taste .
The procedure for preparing V. kirkii (Baker) J.B.Gillett and S. obtusifolia (L.) H.S.Irwin & Barneby vegetable sauce is similar, namely plucking fresh leaves, brief wilting under direct sunlight for approximately 30 min, washing, and then boiling. In order to ensure proper cooking, local salt called “Abalang” (filtrate from ash of selected plants) is added, and then, sodium chloride is added to give a good taste. This can be eaten at this stage, or sour milk, groundnut, or simsim paste are added to spice it (Plate 1). The peculiarity in Maerua angolensis DC, and L. hastata, is pounding (using a mortar and pestle) after boiling and no addition of the local salt. In the case of Dioscera sp. tubers, they are washed (occasionally peeled), boiled, and salted (sodium chloride), and it is ready to be eaten.
According to the optimal foraging theory , the results obtained in this study imply that the most economically advantageous foraging pattern is eating fruits. This theory asserts that although obtaining food provides an individual with energy, searching and capturing it also requires energy and time. This underpinning ably explains why adults interviewed abandoned the consumption of certain plants such as S. innocua and S. birrea to children although they are familiar with them but the energy and time invested in obtaining them is not commensurate with the resultant value. This tendency has also been reported in Zimbabwe [9, 48]. Generally, humans contemplate the choice of their food by considering its nutritional benefit together with the cost of searching, handling, and collecting it .
The lack of respondent agreement on the use of gum as food (Table 3) is largely because it is only chewed without swallowing in worse-case scenarios of hunger. It is also probable that this observation is an outlier. However, the loss of indigenous knowledge about edible wild plants  change in the livelihood patterns that limit the amount of time spent foraging in the wild  and a general shift from gathered to purchased foods as rural communities join the market economy  could be responsible for this scenario. Whereas the gatherer to purchaser scenario exists in Teso-Karamoja, the most applicable scenario could be described as gatherer to purchased, cultivated, and sometimes donated (relief) food.
The relatively high importance of wild edible plants in the rainy season coincides with the time when most species are re-sprouting, flowering, and fruiting, thereby increasing their availability. It ought to be stressed that during the rainy season, most households are able to produce food from a range of crops and therefore have a wide range of choice, but still wild edible plants are important. In the dry season, communities are solely dependent on stored food and the wild edible plants (especially vegetables) help to diversify the food intake. This seasonal relative importance greatly impacts households’ food and nutritional insecurity copying ability. Earlier scholars have asserted that in times of food scarcity, wild edible plants make human diets more diverse and add flavor, vitamins, and minerals . Globally, wild edible plants have been recognized as a key component in ecosystem-based adaptation  and food scarcity copying strategy .
The factors put forward for using wild edible plants in Teso-Karamoja region exemplify the vital role they play in the community. Therefore, even if every rural household had enough food in this region, the use of wild edible plants would still exist. There is a need to ensure that the biological resources and the associated indigenous knowledge are safeguarded for posterity, where both the biological resources and the cultural heritage of these communities shall be preserved. It has also been established that wild edible plants harbor great cultural significance to rural populations in developing countries  and their attachment to culture partly explains why the ancient hunter-gatherer tradition still persists in some African communities [9, 15]. This conforms to the proposition of the versatility hypothesis that people are more likely to retain their knowledge and the use and access to a plant that has a greater value for humans .
All the methods used to harvest wild edible plants in this region can be termed as rudimentary and therefore pose less deleterious effects to the plant species. However, where they involve cutting of branches in order to pluck off edible vegetables such as in B. aegyptiaca and M. angolensis, the growth and survival of the plant is greatly hampered. Another deleterious example is the collection of the tubers by digging. These cases imply that forest reserve management plans ought to consider regulated collection of such peculiar plants in order to minimize any detrimental effects. Awareness that most rural communities in Teso-Karamoja region (Uganda generally) feel aggrieved by most forest conservation measures, streamlining the collection of wild edible plants as a trade-off could be a step towards garnering the support of these communities.
The most threatened plant species encountered in this study is P. axilliflorum. This is an endangered species which is endemic to the Democratic Republic and Congo (DRC) and Uganda . In Uganda, it was only recorded in Budongo Central Forest Reserve and Lake Mburo National Park . The current finding is therefore an important step in improving the understanding of the species’ biogeography. Almost all the wild edible plant species in this area have uncertain conservation status (not evaluated) (Fig. 8), yet it is generally accepted that lack of suitable data for prioritizing conservation action greatly hampers plant conservation efforts . However, it should be noted that some of the taxa in the not evaluated category are cosmopolitan species. Some of them are in the family Amaranthaceae which constitute most weeds and secondary crops occurring abundantly in different ecological areas. T. indica has been assessed as vulnerable by the National Red List of Uganda  but has not been assessed by the IUCN.
The wild edible plants in Teso-Karamoja region ultimately offer various benefits and opportunities to the dependent communities. These plants present a cheap means of enriching the diets, creating employment, and diversifying the livelihoods of rural communities in the rural communities of Teso-Karamoja region. There are already some isolated individuals and trade companies exploiting the collection of gum Arabic from Senegalia senegal (L.) Britton, shea nuts from V. paradoaxa, tamarinds from T. indica, and desert date from B. aegyptiaca. Other initiatives include making of wine from S. innocua, B. schleronuera, V. madiensis, and C. spinarum. However, the challenge is that these initiatives are highly fragmented, uncoordinated, and poorly documented, thereby preventing the realization of their full potential.