In this study, a total of 50 species of UWEPs distributed into 39 genera and 30 families were gathered and documented from the study area (Table 2). All the UWEPs were reported by the local community with their vernacular names. Out of these total reports, 36 species (72%), 25 species (50%), 22 species (44%), 21 species (42%), 18 species (36%), 17 species (34%), and 13 species (26%) were reported in the study conducted by [3] at the country level, by [36] in Soro District, southern Ethiopia, by [37] in Berehet District, North Shewa Zone of Amhara Region, by [38] in Muja District, northwestern Ethiopia, by [11] in southern Ethiopia, by [39] in West Gojjam, Ethiopia, and by [40] in Mieso District, eastern Ethiopia, as wild edible plant species, respectively, and 12 species (24%) were reported in a similar ethnobotanical study conducted by [12] in the Chilga District, northwestern Ethiopia. The number of UWEPs recorded in the study area was lower than the number of wild edible plants reported by [6, 11, 36] in other parts of Ethiopia. But it was greater than the number of wild edible plants reported in several ethnobotanical studies (e.g., [12, 38,39,40,41,42]) and compared to the number of species reported as wild edibles in other regions of Ethiopia [37, 43, 44]. The relatively higher number indicates that the catchment under study was generally endowed with diverse and rich sources of UWEPs with their associated indigenous knowledge, and such high diversity might be due to the existence of different agroecological zones in the study area. The possible variation among different localities of the country could be due to the existence of variations in community culture, vegetation cover, the size of the study area, and environmental conditions. After evaluating the country's endemic plant report [45], and through assessing the ethnobotanical wild edible plants review report at country level by [7] and other similar study reports in the country, out of the total documented species, two species (Impatiens rothii Hook. f. and Urtica simensis Steudel) were endemic to the country, and three species, Canarina eminii Asch. and Schweinf, Gardenia terniffolia Schumach and Thonn, and I. rothii, which were not previously known as edible plants, were newly discovered and added to the wild edible database of the country.

The highest number of these UWEPs was found in the family Moraceae (4 species, 8%), followed by Fabaceae, Flacourtaceae, Myrtaceae, Rosaceae, and Tiliaceae (each contributed 3 species, 6%). Those species in the family Moraceae were contributed by 4 genera (10.3%), in Fabaceae by 3 genera (7.7%), in Flacourtaceae, Rosaceae, and Tiliaceae each by 2 genera (5.1%), and in Myrtaceae by 1 genus (2.6%). The remaining 7 families and 17 families each contributed two species (4% each) and one species (2%), respectively. Thus, 43.3% of the families were represented by more than one UWEP species. One or more of these families with the highest edible species contribution were consistently recorded in different ethnobotanical wild edible inventories [3, 7, 38, 40, 42, 46]. In particular, Moraceaea, Fabaceae, and Tiliaceae were mentioned for their highest number of wild edible resource contributions in different parts of the country [7]. The distribution could be attributed to their wider distribution throughout various agroecological zones all over the country. At the genus taxonomic level, the genera Ficus (4 species), followed by Grewia and Syzygium (3 species each), contributed the highest number of species. Either one or more of these highly wild food-contributing genera were also recorded elsewhere in Ethiopia [38, 40, 47].

The habitat distribution of the surveyed UWEPs covered a diverse ecological range from low to high land (1290–3058 m) above sea level. Explored habitat analysis showed that the species were recorded from a variety of habitat reservoirs. About 35 species (70.0%) were found in the forest, followed by pasture and grassland (24 species, 46.0%), riverine and home gardens (each 14 species, 28.0%), farm and arable lands (12 species, 24.0%), and the other possible habitat areas indicated in Table 2. A low diversity of plant species was recorded from the highlands, while a larger diversity of species was recorded from the midlands and lowlands (Fig. 3). This could be an indication that the local communities in these two agroecologies have retained more indigenous knowledge of their quoted plants. Similarly, the study conducted on prospects for sustainable use and development of wild food plants [3] and the ethnobotanical study of edible wild plants in Ensaro district, Amhara regional state [42] in Ethiopia indicated that the midland and lowland agroecology of the country were highly enriched by wild food plants, whereas the highland was known for low diversity, and areas with higher elevations are mostly known for their limited plant diversity [48].

Habit analysis of UWEPs used as edible food during different conditions in the study area revealed that shrubs constituted the largest category (22 species, 44%), followed by trees (18 species, 36%), whereas herbs consisted of the lowest life form (10 species, 20%) (Fig. 2). Our finding was agreed with the previous study reports [6, 37, 38, 40], which reveal that the predominant source of underutilized wild edibles was shrubs and trees. The review report analysis done by [7] at the country level also reveals that shrubs occupied the dominant position in contributing wild edible resources, followed by trees, herbs, and climbers. The study conducted in Nhema communal area, midlands province, Zimbabwe, by [49] also indicated that wild edible plant resources were mainly from trees and shrubs. In contrast to our study report, [50] reported the dominance of herbs followed by shrubs in an ethnobotanical study conducted in Burji District, Southern Ethiopia. On the other hand, the study conducted by [36], which indicated that trees, followed by herbs, contributed the most edible resources, also contrasts our findings.

Habit of underutilized wild edible plants used in Midakegn District

In this finding, a total of 53 UWEP parts were used as food in the study district under different circumstances. This includes fruits, leaves, leaves and stems, gums or exudates, seeds, young shoots, flowers, root tubers, nectars, and twings (Table 3 and Fig. 3). A smaller number of edibles (34%) were reported in the highland when compared to those reported in the midland and lowland of the study area (69.8% and 67.9 species, respectively). UWEPs commonly harvested for their fruits accounted for 33 species (62.3%), followed by plants harvested for their leaves and stems (5 species, 9.4%), and leaves alone (4 species, 7.5%), whereas those collected for other parts accounted for 20.8%. The study reports on UWEPs in the Chilga district, northwest Ethiopia, by [12] and in Tigray, northern Ethiopia, by [43] also indicated that fruits were the most commonly used parts of UWEPs. Similar to this finding, [7, 11, 20, 40, 46, 52] reported that fruits were the most widely used parts compared to the others. This is also similar to the report [4], in which fruits shared the majority of underutilized wild edible parts in the Asian Pacific region. The study report [53] in Indonesia also indicated that fruits, particularly those from the wild, are plentiful but less well known and underutilized. A cross-comparison of underutilized plant parts commonly reported in the three agroecologies has revealed a high degree of heterogeneity, and only a small proportion (7 species, 13.2%) of the food uses of certain recorded plant parts were commonly shared among the three agroecological areas (Fig. 3A). In between the three groups (Fig. 3B), maximum homogeneity was recorded between lowland and midland (22 species, 41.5%), followed by midland and highland (9 species, 17.0%), whereas minimum homogeneity was recorded between highland and lowland (7 species, 13.1%). This could be due to variation in altitudinal and other environmental factors that determine plant diversity in the environment. Different natural environments may lead to different plant utilizations [54]. As altitudinal variation increases, the common plant tax shared between the agroecologies of the study area decreases. This is why the minimum homogeneity of UWEP parts between lowland and highland and the relatively maximum homogeneity between lowland and midland and midland and highland were recorded in the study area. The remarkable heterogeneity in the use of wild edible plants among different groups could be referred to as the lack of common practice between different communities [48].

Venn diagrams show cross-comparisons of UWEP parts in use in the study area. A shows overall homogeneity and heterogeneity among the three agroecologies; B shows homogeneity between agroecologies

The local community uses 67.3% and 25% of the quoted edible parts to supplement staple food and as emergency food, respectively, whereas UWEP parts chewed during the drought and utilized to get relief trust each account for 3.8%. Edible plant parts from the wild are used as supplementary, seasonal, or survival food sources in various cultural groups in Ethiopia [7]. They support the rural livelihoods of the local community both during ample food production and during the need for emergency safety nets in conditions of food shortage, famine, and poverty [17, 37, 55] and hence play a role in combating food insecurity, especially for rural poor communities. They play a significant role in the subsistence and economy of resource-poor people throughout developing countries [18].

The local community quoted 53 plant parts from the total species reported in this study area. Out of these, 41 edible parts (77.4%) were directly consumed without further processing, whereas 12 plant parts (22.6%) needed further processing prior to use as food. Those edible parts were mainly consumed as fruits (62.3%), followed by those consumed as vegetables (9.6%). Others were consumed in the form of chewing (7.7%), spices (5.8%), condiments (5.8%), nectar sucking (3.8%), bread and/or “Injera” (1.9%), and other forms (1.9%). The main mode of consumption (80.4%) was direct utilization of raw fresh or raw dried edibles, followed by those consumed after cooking (9.8%) and fermentation (5.8%), respectively (Fig. 4). According to study findings from different regions of Ethiopia [6, 37, 40, 52], Zimbabwe [51], and Sudan [56], raw consumption was noted as the main way that people consumed wild edible foods.

Consumption pattern of underutilized wild edible plants, A indicates the form of consumption, B indicates the mode of consumption

According to the study area respondents, all the recorded fruits were directly consumed raw outdoors in the fields while working, keeping livestock, and traveling from place to place. The wide use of fruits is due to their ease of processing, more preferable taste, day-to-day requirements, and nutritional value [6, 38], the taste quality reduction during preservation, and the difficulty of preserving plenty of fruits for the indigenous people [49]. For instance, fruits of S. afromontanum, S. guineense subsp. guineense, F. indicia, M. kummel, X. americana, R. steudneri, F. sur, D. abyssinica, R. apetalus, C. spinarium, R. abyssinica, and C. africana relatively had more appreciation among the local communities and were consumed as supplementary food. In the review report [7], all of those species were listed among the common sources of edible fruits elsewhere in Ethiopia. The same is true for C. africana and F. sycomorous in Sudan [56]. There were also raw fruits, which received no more appreciation among the local community but served as supplementary food in the study area. Freshly ripened fruits of G. bicolor, G. ferruginea, G. Villosa, E. racemosa, M. africana, P. peruviana, S. comorensis, and T. nobilis were eaten raw outdoors by all community members except the fruits of P. peruviana, which were mainly considered children's food. However, harvesting of fresh edibles for consumption from some species, such as F. vasta, F. sycomorous, E. kapensis, F. thinningii, G. terniffolia, R. glutinosa, and P. reclinata, was most commonly to alleviate starvation during famine. In this case, both sexes and all age groups of both wealth classes, especially the elders, tried to access those edibles as alternative sources only during famine. This suggests that the majority of local communities continue to undervalue the potential use of the resources. But whenever edible resources were available, even when there was no scarcity of food, mostly youngsters and herdsmen search for collection and enjoyed consumption in the field. However, consuming excessive amounts of particular fruits, such as F. sura, F. vasta, F. sycomorus, and F. thonningii, whether raw or dried, has been linked to gastrointestinal discomfort. Similar to this, [46] stated that in the region of Konso ethnic communities in South Ethiopia, stomach pain and diarrhea are common health problems following the consumption of numerous wild edible plants. Fruits were not the only edibles eaten raw; other parts were also utilized raw and fresh without needing further processing. During times of drought, the local population chewed raw gums of V. abyssinica and F. albida as well as fresh, just emerged lateral and terminal shoots of R. nervosus, mostly to reduce their need for water. Underground root tubers of E. cardifolium were chewed raw by children, particularly when keeping cattle. Children in the study area also used the flowers of I. rothii and J. schimperiana to suck the nectar that provided them energy. A fresh flower cavity of C. eminii was filled with either fruits of R. steudneri, R. apetalus, or R. abyssinica, which were consumed together by children in the study area. In addition to the fruits consumed as supplementary food, twigs of E. racemosa were chewed by all community members to get refreshment.

On the other hand, only 22.6% of edible parts that needed cooking, backing, condimenting, and spicing were brought home before dish preparation and were consumed by all family members in the home. This result agreed with the finding of [52], in which a few wild edible plant parts were brought home for cooking before consumption, and dishes prepared from them were consumed by entire groups [57]. But cooking responsibilities were accomplished by women and female youngsters in the study area. For instance, the collection and preparation of the leaves of A. hybridus, the leaf and stem of U. simensis, and the young shoot of O. alpina as vegetables mainly during food scarcity were done by women and young girls. Even though it was a very rare species in the study area, the root tubers of C. esculenta were also cooked by women and consumed as vegetables in the study area. Similarly, powdered grain seeds of S. pyramidalis were backed into bread, or "injera," just like Eragrostis tef (Zucc.) Trotter flour and seeds of F. albida were cooked into boiled grain, or "Mulluu," by women and young girls and consumed by all family members during the famine. Women also mainly participated in the leaf collection of O. europaea L. subsp. cuspidata, R. staddo, and G. amygdalinum for use as additives in the fermentation process of different local alcohols, such as "areke," "tela," and "teji". Also, commonly, harvesting the leaves of L. adoenesis and T. schimperi and using them in the spicing or flavoring process was done by women. The review report done on the contribution of indigenous food preparation and preservation techniques for the attainment of food security in Ethiopia [57] indicates that leafy wild edible material collection and processing for consumption are mostly considered the responsibility of women and young girls in Ethiopia. The leaves and stems of L. adoenesis var. adoenesis and L. adoenesis var. koseret were used for various food additive spicing purposes (e.g., pepper powder, butter, etc.), and T. schimperi was used as tea flavoring. Milk pots and other kitchen equipment were also cleaned and fragranced with the leaves of the two L. adoenesis varieties in the study area. The Gurage and Oromo peoples use the fragrant leaves as one of the spices for making spiced butter [35]. Food prepared with spiced butter and/or spiced pepper powder had a delicious flavor that attracted people to eat it. In addition to all these recorded underutilized edibles from the wild that were used to maintain the sustainability of food security and food sovereignty in the study area, they have more contributions than the locals are aware of. Especially for the local poor, their utilization not only assures food security but also supplies vital nutrients that prevent malnutrition. As [58] reported, consumption of wild edible fruit provides more nutritional value, such as vitamins, fibers, and secondary metabolites, to the human diet than cultivated crops, and they have a good content of minerals (cupper, magnesium, and phosphorous), carotenoids, and protein. The nutritional composition analysis done on underutilized edible fruits of Balanites aegyptiaca (L.), Grewia flavescens Juss., and Ziziphus spina-christi Willd. also indicated that their fruits are enriched with major food substances such as carbohydrate, crude protein, crude fat, and minerals [17]. On the other hand, proximate amino acids, minerals, and ant-nutritional factors analysis of popularly consumed fifteen wild edible plants in Hamar and Konso of southern Ethiopia also revealed that wild leafy vegetables contribute good amounts of these essential nutrients to the human diet [