Socio-demographics of the informants

The ethnobotanical study conducted in the Quara district has yielded valuable insights into the socio-demographic factors influencing the knowledge and utilization of medicinal plants in the local community. Accordingly, the study found that men were more knowledgeable about medicinal plants than women. In the study area, men were more likely to be exposed to social affairs, which facilitates their acquisition of knowledge. Our data support the findings of [75, 76] who reported similar outcomes.

It was also found that older informants, aged 60 years and above, demonstrated a higher level of knowledge of medicinal plants compared to the younger age groups (20–39 years and 40–59 years). This aligns with the findings of previous research [46], which suggest that the older generation’s extended cultural exposure, exchange, and practical experience contribute to their greater knowledge in this domain. Studies also identified a concerning trend that the indigenous knowledge on the use of medicinal plants is deteriorating due to the passing away of the knowledgeable older generation before they can effectively transfer their knowledge to the next generation [49, 77, 78]. This challenge is exacerbated by the younger generation’s lack of interest in learning from their elders. As a result, there is a risk of losing this invaluable indigenous wisdom as the older members of the community pass away.

Among the three informant groups categorized by educational level, those who could read and write cited the highest number of medicinal plants, followed by illiterate informants, and those with formal education. This finding is consistent with other studies [49, 78], which suggest that lower levels of education are associated with greater knowledge of medicinal plants, possibly due to the impact of modern education [10]. The ability of those who can read and write to recall and utilize the medicinal plants they are familiar with may be connected to their overall higher level of knowledge compared to the illiterates. This finding highlights the complex interplay between formal education, literacy, and the retention and application of traditional medicinal plant knowledge.

Key informants, such as herbal practitioners, cited more medicinal plants than the general informants, reflecting their full-time experience in utilizing these plants for treatment, as supported by previous research [49]. Although settlers (both formal and informal) and local inhabitants coexist harmoniously, the local inhabitants mentioned a larger number of medicinal plants compared to settlers. This could be because local inhabitants have lived in the area for a longer period and are therefore more familiar with the plants that grow there. The Gumuz ethnic group was found to be the most knowledgeable about medicinal plants compared to other ethnic groups in the study area. This can be attributed to the Gumuz people’s heavy reliance on flora and fauna for their health and everyday survival, as well as the exchange of indigenous knowledge, particularly medicinal plant knowledge, within their community and with neighboring Sudan.

Medicinal plant diversity

The study identified a rich diversity of medicinal plants used to treat human ailments in the Quara district, with a total of 128 medicinal plant species documented. This figure exceeds the counts reported in recent ethnobotanical studies conducted in other parts of Ethiopia. As an example, studies in the Raya Kobo [7], Suro Barguda [13], Artuma Fursi [66], Asagirt [49], and Ensaro [63] districts recorded 74, 98, 92, 103, and 101 medicinal plant species, respectively. Several factors may contribute to the greater number of medicinal plants utilized in the Quara district. These include ethnic diversity in the area, and the influx of settlers from different parts of the Amhara region; the rich plant diversity, particularly due to the presence of communal forest areas; the district’s proximity to Sudan, which has facilitated the exchange of indigenous knowledge; the remote location of the area and inadequate access to formal healthcare, leading the community to rely more on traditional medicine; and the prevalence of various human ailments, such as febrile illness, evil eye, evil spirit, snakebite, spider sting, tonsillitis, wound healing, intestinal parasites, diarrhea, and amoebiasis, which may necessitate the use of a broader range of therapeutic plant species (see Supplementary Material 1). Furthermore, the large number of recorded medicinal plant species emphasizes the continued relevance and indispensability of plant-based remedies in fulfilling the primary healthcare requirements of the population, particularly in areas with limited access to conventional medical services.

The dominance of the Fabaceae family among the medicinal plants identified can be attributed to the evolutionary adaptations of this plant family in the local environment. The ability of Fabaceae species to form symbiotic relationships and thrive in nitrogen-deficient soils, as well as their capacity to develop extensive root systems and outcompete other plants for resources, provides them with a competitive advantage in the area [79, 80]. This finding is consistent with previous ethnobotanical studies conducted in Ethiopia [49, 78, 81], and other parts of the world [82,83,84].

Regarding the habit of medicinal plants, the study found that the people of the Quara district utilized trees and herbs in nearly equal proportions. This observation aligns with the findings of a previous ethnobotanical study conducted in Ethiopia [78, 85], where a similar pattern was reported. However, it is important to note that in some other ethnobotanical studies, shrubs were reported to be the most widely used medicinal plant habit [13, 66, 75]. This variation may be attributed to differences in the local plant community composition and ecological conditions. Lowland areas with sufficient rainfall, like the Quara district, are typically dominated by woody species, forming woodlands, which could explain the prominence of trees and underneath herbs as medicinal plants in the present study.

Plant parts and the conditions for preparing remedies

The study found that the most commonly used plant parts for remedy preparation were leaves, followed closely by roots. This observation is consistent with the findings of many other ethnobotanical studies conducted in Ethiopia [13, 46, 77, 78] and globally [83, 86]. The predominant use of leaves for remedy preparation in the study area can be attributed to several factors such as easy accessibility, abundantly availability, and their primary site for the accumulation of many bioactive compounds. Furthermore, picking leaves has less effect on the plant species’ survival. While roots have been reported as the most frequently used plant parts in a few other studies [75, 82, 87], the extensive use of roots can pose a risk to the long-term survival of medicinal plant populations [8, 88].

Consistent with previous studies conducted in Ethiopia [10, 49, 89], the majority of the remedies in the Quara district were prepared using fresh plant parts. The use of fresh plant materials is generally associated with higher efficiency of the bioactive components [75]. However, the fact that most of the medicinal plants in the study area were trees, and the fresh parts were primarily collected, suggests that the availability of remedies may have been limited to certain seasons of the year, as many trees shed their leaves during the dry season.

Ailments treated with medicinal plants

The analysis of the data on the diversity of medicinal plant use revealed that more than three-quarters of the identified species were employed to treat multiple diseases. This finding suggests a widespread adoption and utilization of these medicinal plants by the local community, which agrees with [90]. The versatility of many medicinal plants reported in this study for treating different health conditions may be attributed to the combined action of the various bioactive constituents present in these plants. In association with this finding, [91] reported that the synergistic effects of the different medicinal components can potentially enhance the catalytic activity and facilitate the absorption of the beneficial compounds in the human body. These findings highlight the need for further scientific investigation into the phytochemical profiles and pharmacological properties of these versatile medicinal plants. Unraveling the underlying mechanisms that enable certain medicinal plants to treat a diverse array of ailments can contribute significantly to the development of more effective and holistic traditional medicine practices. This knowledge can be instrumental in improving the overall health and well-being of the local population.

Methods of preparation and route of administration of remedies

The study found that the most frequent methods of preparing medicinal remedies in the Quara district were extraction, decoction, paste, and chewing. These preparation methods align with the findings of previous ethnobotanical studies conducted in different regions [51, 92, 93]. The informants reported that there was no standardized approach to administering the remedies, and the method varied depending on factors such as the patient’s age and health condition. This observation is consistent with the findings of other studies [94], indicating the flexibility and patient-specific nature of traditional medicine practices. Oral administration was identified as the primary route of delivering herbal remedies in the Quara district. This observation is in line with the findings of other ethnobotanical studies, which have also reported the oral route as the predominant mode of administration for traditional medicines [49, 95]. The diversity of preparation techniques and administration routes observed in the study highlights the depth of traditional knowledge within the local community. Healers and practitioners likely adjust their approaches based on the specific needs and conditions of the patients, drawing from a wealth of experiential knowledge accumulated over generations.

Ethnobotanical knowledge distribution among ethnic groups

The study found that more than a quarter (28%) of the medicinal plants were mentioned across all three ethnic groups. However, the Amhara ethnic group reported a greater number of medicinal plants compared to the other groups. The higher mention of medicinal plants by the Amhara is likely due to their large population size and extensive agricultural land coverage in the area. Additionally, the seasonal movement of the Amhara people from neighboring highland districts to Quara for farming and livestock rearing may have facilitated the sharing of medicinal plant knowledge within their community. In contrast, the Agew ethnic group reported a smaller number of medicinal plants, possibly due to the secretive nature of their traditional knowledge, which is a common phenomenon observed in many traditional communities. The findings of this study, as well as several previous studies [96,97,98], emphasize that the diversity of medicinal plant knowledge is often influenced by the ethnicity and cultural background of the communities. These insights underscore the importance of considering the ethnic and cultural context when documenting and understanding traditional medicinal plant knowledge.

Informant consensus factor

The study reported ICF values ranging from 0.75 to 0.03 indicating a strong consensus among the informants regarding the therapeutic uses and efficacy of certain medicinal plant species, as described in [99]. The highest ICF value of 0.93 was observed for diseases related to the circulatory system and blood/blood-forming organs. This aligns with findings from other studies [100, 101] and suggests that the local community has confidence in the medicinal plants of the study area for treating these types of conditions. Specifically, hypertension and anemia were the two diseases highlighted in this high consensus category, with 71 and 15 use citations, respectively. Among the three species reported to treat hypertension, Moringa stenopetala had the most citations, with 67 use reports. The informants mentioned that hypertension can be effectively treated by boiling the leaves of Moringa stenopetala and consuming the resulting decoction as tea.

The second-highest ICF value was recorded for the category of infectious and parasitic diseases. This finding is consistent with the results reported in [102], which found high ICF values for viral, fungal, bacterial, and other parasitic infections. Within this category, Malaria had the highest number of use reports, with a total of 118 use reports. Azadirachta indica was the most cited species for treating malaria. The highest use report of Azadirachta indica could be attributed to its ability to adapt to local environments and its effectiveness in conventional uses. Informants indicated that malaria can be treated by either boiling the plant parts or consuming the decoction once it has cooled or by crushing the stem bark, adding water, and drinking the resulting fluid.

The use of multiple species reported for diseases and symptoms related to the digestive system is likely attributed to factors such as malnutrition, poor hygiene, irregular dietary routines, and contaminated drinking water [103]. A high ICF can be an indication of potentially effective medicinal plants [35]. These findings indicate that the local community has a well-established and shared knowledge base regarding the therapeutic efficacy of certain medicinal plants, particularly for circulatory and blood-related conditions. This high level of consensus can help prioritize these medicinal plants for further phytochemical and pharmacological investigations, as well as inform the development of culturally relevant healthcare interventions.

Rahman’s similarity index

The highest RSI of 12.93% was found in a study carried out in the Metema district of northwestern Ethiopia [43]. This was followed by studies in the Habru district of northcentral Ethiopia with an RSI of 11.48% [51] and in the Hawassa, Shashemene, and Dilla districts of southcentral Ethiopia with an RSI of 10% [54]. Northern Ethiopian districts like the Adwa (RSI = 9.47%) [46], the Erob and Gulomahda districts (RSI = 9.31%) [47], and the Kilte Awulalo district (RSI = 9.09%) [44] also had higher RSI values. The RSI gradually decreased from the northern, northwestern, northcentral, and southcentral regions to the western, southwestern, southern, southeastern, and northeastern regions of the country.

The high RSI between the current study and Metema district [43] can be attributed to the geographical proximity of these two neighboring districts. The similarities observed with other regions in the northwestern, northern, northcentral, and northeastern parts of Ethiopia can be explained by factors such as geography, cultural practice, and vegetation coverage [82, 104]. The gradual decrease in RSI from the northern to southern areas is likely influenced by the distance and geographical barriers that impede the exchange of information on the use of ethnomedicinal plants [82, 105]. These findings suggest that the use of traditional medicinal plants is more homogeneous in geographically proximate and culturally similar regions, while diversity increases with distance and geographic barriers. This highlights the importance of considering regional and cultural factors when studying traditional plant-based healthcare practices.

Direct matrix ranking

The DMR exercise helped to determine the most heavily used multipurpose plant species in the Quara district, as well as the factors posing a threat to these plants. Accordingly, the top three most used multipurpose plant species were Ziziphus spina-christi, Terminalia leiocarpa, and Ficus sycomorus. These plants are currently exploited primarily for their medicinal properties rather than their non-medicinal uses. This finding aligns with previous research [106] that highlighted the use of medicinal plants for medicinal purposes as the primary threat among the five threats evaluated in the DMR exercise. The specific plant parts utilized for medicinal purposes play a crucial role in determining whether a plant is at risk. For instance, the root, root bark, and stem bark of Ziziphus spina-christi are used for various ailments, increasing the susceptibility of this plant to threats. Similarly, the stem and stem bark of Terminalia leiocarpa are utilized for treating different ailments, leading to its vulnerability. The findings from the DMR exercise suggest that the overexploitation of these multipurpose plants, particularly for their medicinal uses, poses a significant threat to their sustainability in the Quara district. This highlights the need for conservation strategies that consider the balance between medicinal and non-medicinal uses of these important plant resources.

Novel ethnobotanical findings

Out of the 128 medicinal plant species identified in the current study, 80 of them had been previously reported to have the same uses. This suggests a strong cultural exchange of traditional plant-based healthcare practices among communities across Ethiopia [55]. From the remaining 48 species, there were nine new reports of medicinal plants in Ethiopia, highlighting the incredible biodiversity of the area studied. Notably, two of these medicinal plants–Dracaena forskaliana and Ipomoea biflora–were not reported elsewhere in the world, making them novel global discoveries as well. The identification of these two species as new medicinal plants is particularly remarkable, as it suggests that the traditional health practices of the local communities in the Quara district encompass the utilization of plant resources that have not been recognized for their medicinal properties elsewhere. These discoveries expand the existing knowledge of traditional medicinal applications of plants in the Quara district. In addition to the new medicinal plant species, the study also reported 39 new use cases for plants that were already known. For instance, the study revealed that the leaf of Rumex nepalensis is used to treat malaria, whereas previous studies had reported its use for 24 different ailments [29, 30, 39,40,41,42, 45,46,47, 49, 51,