The findings of the present investigation revealed the widespread use of WEPs in times of food scarcity as well as food supplementation in the Heban-Arsi and Kofale districts, Oromia Regional State, Ethiopia, as evidenced by the extensive diversity of WEP species documented (Table 3). The Moraceae family was represented by 7 species and was followed by Fabaceae (4 species), Rubiaceae (4 species), and Lamiaceae (3 species). Previous studies on WEPs also reported a greater abundance of plant species from the Moraceae family with 6 and 11 species documented in the study conducted by [37, 60], respectively, in Ethiopia. On contrary, some earlier studies in other parts of Ethiopia showed that the Fabaceae family was reported to be dominant families in Ensaro district, Amhara regional state, Ethiopia, with 4 species [38, 48, 56] reporting highest contribution of Rubiaceae family (5 species) in Dibatie district, Metekel zone, Benishangul Gumuz Regional State, western Ethiopia. Other study [61] reported the Lamiaceae as dominant family in Tiyo district, Arsi Zone, Oromia, Ethiopia. The distribution of these families could attribute to their wider growth throughout various agro-ecological zones all over the country [59]. At the genus taxonomic level, the genera Ficus and Grewia (3 species each) contributed the highest number of species in study areas. Grewia was also reported as abundant wild food contributing genera (3 species) elsewhere in Ethiopia [28].

The Moraceae family often called the mulberry family is flowering plants comprising about 40 genera and over 1,000 species. Most are widespread in tropical and subtropical regions [62]. The Fabaceae family encompasses over 20 genera and its members are adaptable to a range of environments and are economically significant [63]. The food crops within this family provide high levels of protein and essential micronutrients, which are crucial for improving livelihoods and health [63]. Particularly in developing countries, the therapeutic benefits of the Fabaceae family are well recognized [64].

In general, 62 species of WEPs were identified in the surveyed districts and were higher compared to the numbers reported in other regions of the country: 41 species [28], 38 species [65], and 54 species [56]. However, the number of WEPs reported by the current study was lower than those reported by previous studies by different researchers, respectively, reporting 71 [66], 64 [50], and 66 [11] WEPs in Ethiopia. This disparity in the number of reported wild edible plants could be due to differences in culture, vegetation cover of the area, or climatic variation and the existence of different agro-ecological zones in the study districts [59, 67].

In comparison with previous ethnobotanical studies, most of the edible plants identified in this study have also been reported as edible in other regions of Ethiopia. For example, 24 species were documented in the study conducted in Arsi Robe district of East Arsi Zone, Ethiopia [46], 22 species in Dibatie district, Metekel zone, Benishangul Gumuz Regional State, western Ethiopia [56], 21 species in pastoral and agro-pastoral communities of Mieso district, eastern Ethiopia [28], and 20 species were documented in Midakegn district, West Shewa Zone, Central Ethiopia [59]. In addition, the studies conducted by [60] in the Awi Agäw community, northwestern Ethiopia (17 species), [68] in the Sedie Muja District, South Gondar Zone, northwestern Ethiopia (15 species), [69] in the Berek Natural Forest, Oromia Special Zone, Ethiopia (14 species), and [70] in the East Hararghe Zone, Oromia, Ethiopia (11 species), all showed overlaps of WEPs with the current study. The similarity in the distribution of WEPs and their traditional uses may be attributed to the geographical proximity and cultural exchange among local communities residing in these different regions [56].

Out of the 62 recorded WEPs in the study area, 4 species, such as Galiniera saxifraga Hochst. Bridson, Ficus ruspolii Warb. Ranunculus multifidus Forssk, and Myrsine melanophloeos (L.) R.Br. ex Sweet were not reported in the previous studies conducted in different parts of Ethiopia, as well as in 413 WEPs reviewed by [20]. On the other hand, some WEPs, such as Balanites aegyptiaca (L.) Delile, Ficus sycomorus L. Carissa spinarum L, Syzygium guineense (Willd.) DC, and Ximenia americana L., were highly reported by the previous studies and widely consumed in many areas of the country [28, 56, 59].

Comparative analysis of the two studied districts revealed that the greatest diversity of WEPs (56 species) was collected from the Heban-Arsi district and 39 species from the Kofale district. More WEPs consumed in the Heban-Arsi district than in the Kofale districts, which might be due to the availability of large areas of grazing land/fields. More species were collected from lowland and midland areas of Heban-Arsi district (between altitudinal range of 1250 and 2000 m a.s.l.). A high abundance of WEPs in such agro-ecological zones was also reported elsewhere [11] in Ethiopia. Thirty-four species shared between the communities in the two districts. The similarity in wild edible species between the Heban-Arsi and Kofale communities might be attributable to the overlap of their ecological niches, cultures, and languages. Similar observations also reported elsewhere by several researchers [26, 71].

Shrub was the dominant growth form of WEPs in the study districts (32 species, 51.6%), followed by herbs (13 species, 21%). The dominance of wild edible shrubs and herbs might demonstrate the better availability of WEPs for harvesting throughout the year [56]. Similarly, the wide utilization of shrubs also reported in other parts of Ethiopia [42, 72,73,74]. The predominant (12%) use of shrub growth form also reported in Sampang and Pamekasan districts of Indonesia [74]. In contrast, trees were reported as the main sources of wild food in different parts of Ethiopia such as in Dibatie district, Metekel zone, Benishangul Gumuz Regional State, western Ethiopia 38 species [56], and in Soro district, southern Ethiopia 22 species [50].

The habitat distribution of the surveyed WEPs covered a diverse ecological range from low to high land (1350–2736 m, a.s.l). The greatest number of WEPs (24 species, 38.7%) was collected from grazing lands/fields, followed by forest habitats (17 species, 27.4%). A similar study conducted by [11] in Ethiopia also found that 62.1% of the wild edible plant species were gathered from wild fields, which supports the findings of our study.

In the current study districts, Fruits were the predominant component of the WEPs consumed 38 (63%) species, followed by Leaves 11 (17.74%) species. In line with the current findings, the dominance of fruit use was also mentioned in other studies in Ethiopia [28, 57]. The studies on (WEPs) in communities near Mabira Central Forest Reserve, Uganda [75], and in Nepal [26], also reported the predominant of 66% and 54.3% fruit plants part used for consumption, respectively. The preference for consuming whole fruits may be due to their convenience, minimal processing, high nutritional benefits, and superior taste and sweetness [11]. Similarly, the fruit parts of WEPs have high nutritional value and secondary metabolites compared to those of cultivated crops [11].

Wild edible leaves are frequently consumed, after fruits, during the summer months when food shortages occur in the study areas. Studies showed that wild edible leaves are a suitable nutrient supplement to a carbohydrate-rich diet of poor rural communities [76]. WEPs leaves are particularly rich in protein, calcium, iron, vitamins and are antioxidants [77] and many are also known for their medicinal properties [14]. Some WEPs have different/alternative edible parts, such as leaves and seeds (Amaranthus dubius Mart. ex Thell.), fruits and shoots (Rumex nervosus Vahl), and stems and fruits (Phoenix reclinata Jacq). The ability of wild edible plants to offer multiple edible parts may enhance their utility and value, supporting diverse dietary needs [78].

Temporal variability in the growth of WEPs species affects their availability [79]. WEPs were collected and consumed in different seasons of the year. The present findings revealed that WEPs collected mainly in the months of March, April, and May. Some WEPs also collected in October, November, and December. The months of March, April, and May were also reported as the major harvesting periods in Mieso district, eastern Ethiopia [28]. The main WEPs collected from March to May were Balanites aegyptiaca (L.) Delile, Carissa spinarum L., Capparis tomentosa Lam., Allophylus abyssinicus (Hochst.) Radlk, and Ficus vasta Forssk.

Food scarcity frequently observed in lowlands and some midland areas of the Heban-Arsi district from June to August. During this period, the majority of rural communities use WEPs as basic sources of food until cultivated agricultural crops mature. A similar report on the use of WEPs during food shortages and famine mentioned in another study in Ethiopia [11, 24]. The use of WEPs during food shortages and famine was also reported in Boumba, Niger [80], and in Bangladesh [81].

The majority of the WEPs 48 (77.4%) in the study districts harvested and utilized in their unprocessed form. Fourteen (14%) of the species were consumed after chopping with a knife and cooking, or roasting, powdering and boiling. A significant portion of the WEPs (41 species, 66%) were exclusively consumed during periods of famine or food shortages, while (21 species, 34%) were used to supplement staple foods. Plants such as Allophylus abyssinicus (Hochst.) Radlk, Balanites aegyptiaca (L.) Delile, Carissa spinarum L., Capparis tomentosa Lam., consumed regularly as supplementary food during their ripening seasons. Conversely, plants such as Vachellia etbaica (Schweinf.) Kyal. & Boatwr, Euclea racemosa subsp. schimperi (A.DC.) F.White, Gallium sp., and Asparagus africanus Lam. were among the wild edible plants consumed specifically during times of food shortage in the study districts. Consumption of raw WEPs have also been observed in various regions of Ethiopia such as in Derashe and Kucha Districts, South Ethiopia [11], in Midakegn District, West Shewa Zone, Central Ethiopia [59], in Nhema communal area midlands province, Zimbabwe [82], and around selected forest reserves of Teso-Karamoja region, Uganda [83].

In preference ranking of WEPs, factors such as taste, availability, accessibility, cultural acceptability, its further needs for pharmacological and nutritional studies, and conservation needs determines the preference of one edible plant over another [82]. In this study, preference ranking exercise conducted on the most commonly used WEPs based on their sweetness and safety. The perceived safety of WEPs according to informants was determined based on the absence of stomachache, bloat, and vomiting after consumption. The findings of the preference ranking exercise indicated that Syzygium guineense, Ficus sycomorus, Allophylus abyssinicus, Ximenia americana, and Grewia ferruginea were ranked from 1 to 5, respectively. The results of the preference ranking exercise showed that informants agreed on the importance of these WEPs, highlighting the need for further research into their nutritional, pharmacological, and safety aspects to support their sustainable use through cultivation and propagation {24].

Ficus sycomorus is an excellent source of iron and a good source of calcium and magnesium [84]. Previous evaluation of methanol crude extracts of Ficus sycomorus suggest that the fruit extracts have significant amounts of total phenolic and flavonoid compounds with potential cytotoxic and antimicrobial activities [85]. The nutritional and medicinal contribution of wild fruit of Ficus sycomorus also reported in Ethiopia by [86]. The presence of essential amino acids such as histidine, isoleucine, lysine, methionine, phenylalanine, and tryptophan in Syzygium guineense fruits was reported by [87] in South Africa. Studies in Ethiopia showed that Syzygium guineense fruits and seeds are valuable sources of bioactive compounds such as phenolic acids, flavonoids and anthocyanins and have strong antioxidant activities [24]. Study by [88] in Brazil showed that the seed of Ximenia americana has strong antioxidant activity which could be attributed to polyphenol and vitamin C contents.

The sustainable use of WEPs is crucial for the environment, food security, and medicine, as these plants are climate-resilient, help address food insecurity and malnutrition, and contribute to improve health [89]. Consequently, WEPs contributes to an improved quality of life and environmental sustainability [90]. These plants are well adapted to their environments and climate fluctuations, contributing to ecosystem resilience in the face of changing climates (7). They support biodiversity by providing essential ecosystem services, such as maintaining soil health, improving water retention, and offering habitats for wildlife (24). Their resilience makes WEPs particularly valuable for farmers in developing countries, as they are better equipped to withstand extreme climate events compared to conventional crops (27). Consequently, the genetic resources of these plants are vital for ensuring long-term food security and sustainability [28].

WEPs offer significant nutritional benefits compared to imported foods, which often contain refined ingredients and sugars that can lead to nutrient deficiencies and diet-related diseases. Unlike these foods, wild vegetables and fruits are typically free from harmful chemicals such as fertilizers, pesticides, and herbicides (7). WEPs are especially important in regions where conventional food sources are scarce or unreliable, providing vital nutrition during times of food shortages or crop failures and helping to mitigate food insecurity (70). Studies show that WEPs are rich in protein, carbohydrates, minerals, and vitamins, particularly B vitamins, which are essential for nutrition, food security, and health (80). Furthermore, these plants are integral to local food traditions and cultural practices, supporting food sovereignty by preserving traditional knowledge and enabling communities to manage their own food resources, thereby fostering self-reliance and reducing dependence on external food systems (69).

The finding of the direct matrix ranking exercise showed that Cordia africana was the top-ranked WEP for its diverse uses in the study area, followed by Syzygium guineense and Vachellia seyal. The greater use value of Cordia africana in the districts was related to its multiple uses, such as medicine, construction, fuel, fence, house furniture, cultural value, shade, gum, spiritual, bee hive, fodder, soil holding, water accumulation/holding during drought and ecological significance. The multipurpose uses of Cordia africana were also reported in Chelia district, West-Central Ethiopia [44], and in Bule Hora Woreda, southern Ethiopia [47]. Panda [91] also reported the multiple uses of WEPs for different uses.

In our study, the primary uses of wild edible plants (WEPs) were identified as medicinal purposes, firewood collection, and fencing, with medicinal use being the most common, followed by firewood collection and fencing (Table 3). A significant majority (83.8%) of WEPs were reported for medicinal applications, addressing a wide range of health issues, including diabetes, liver diseases, cancers, skin disorders, and malaria, diarrhea, and stomach aches [25]. Many of these plants serve dual purposes as both food and medicine, which is a well-established feature of traditional medicinal systems [92]. For example, Syzygium guineense fruit is used as food during food shortages, while its leaves are used to treat diarrhea and hypertension [25]. Similarly, Ximenia americana fruit is consumed as food, while its leaves are used in traditional remedies for wounds, diarrhea, leprosy, fever, headaches, ulcers, and skin problems [41].

In the study area, it was reported that the bark part of Maesa lanceolata Forssk was crushed and boiled and topically applied for the treatment of dermatophilosis. However, its leaves were boiled and drunk for the treatment of diabetes [25]. The ripen fruit of Galiniera saxifraga consumed as wild food by cattle herders in the area. However, its fruit decoction is used for the treatment of malaria and anthrax, and its bark is crushed and boiled and drunk for the treatment tuberculosis in the area [25]. The fruit of Dombeya torrida (J.F. Gmal.) P.Bamps is consumed during food scarcity in the study area. However, its leaves are squeezed and mixed with water and drunk with tea cup to treat snake poison in the Heban-Arsi district. Dried fruits of Capparis tomentosa powdered and the decoction is drunk to enhance male erectile problem in the Heban-Arsi district, while its ripen fruit consumed by cattle herders during the spring season.

In some WEPs, similar parts are used for both food and medicinal purposes. The ability of certain WEPs to serve dual functions enhances their importance by providing nutritional and medicinal benefits, and utilizing the same plant parts for multiple purposes promotes sustainable use of resources. It reduces the need to cultivate separate plants for food and medicine, thereby conserving space, water, and other resources [93, 94].

WEPs play a vital role in supporting the survival and livelihoods of many rural communities, particularly pastoralists, due to their accessibility, local knowledge, and affordability [10]. These plants are especially important for marginalized groups, such as women and children, who are more vulnerable to climate-related shocks like drought [10]. WEPs improve food security by providing nutrition during times of scarcity and famine, and they also contribute to income and have cultural and spiritual significance [12]. For instance, fruits, vegetables, and seeds from WEPs are rich in essential nutrients, addressing nutritional deficiencies in vulnerable populations [13].

WEPs are under threat due to land use changes, climate change, overexploitation, and urbanization, which are decreasing the availability of these resources in the wild and leading to the erosion of traditional knowledge related to their use (Borelli et al. 2020). The current study found that WEPs in the area were particularly endangered by the expansion of agriculture into natural forests, the collection of firewood, and the unsustainable harvesting of these plants for timber production. The ever-increasing loss of these resources might be linked to population overgrowth and the escalation of poverty levels in the study districts. The findings of this study are consistent with other reports in Ethiopia such as in the Chilga district of northwestern Ethiopia [22], in Derashe and Kucha districts, South Ethiopia [11], in Bullen district, northwest Ethiopia [40]. The strong reliance of local communities, particularly unemployed youth, on natural plant resources for generating income to support and sustain their families is a recurring observation in the study districts that poses a challenge to WEP biodiversity management efforts.

Local communities in the study area employ various indigenous strategies for conserving and managing their natural resources. These strategies include cultivating wild edible plants like Asparagus africanus Lam, Amaranthus dubius Mart ex Thell, and Ocimum lamiifolium Hochst. ex Benth. in home gardens for medicinal purposes; Carissa spinarum L. and Zanthoxylum asiatica (L) Appelhans, Groppo & J.Wen for fencing; planting Euclea racemosa subsp. schimperi for shade; and preserving certain plants such as Ficus vasta Forssk and Ficus sycomorus L. due to their cultural and spiritual significance, including their use in worship and spiritual practices under these trees.