2.2. Climate

In Basona Werana District, the geographical distribution is divided into four agro-climatic zones. These are Dega (50%), Woina Dega (46%), Wurch (2%), and Kola (2%). The annual rainfall of the district is 966mm, and the mean annual temperature of the district is 13.3C (Figure 2).

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Figure 2

Climadiagram of the study area from 2020 to 2019 at Debre Birhan Station. Data source: National Metrological Service Agency.

2.3. Reconnaissance Survey and Selection of the Study Sites

Basona Werana is a district of Amhara Region of Ethiopia. A reconnaissance survey was conducted from January 30 to February 15, 2020, to select five kebeles based on the availability of traditional medicine history, practitioners, availability of medicinal plants, altitudinal variation, and distribution of climatic conditions between kebeles. Based on this information, five kebeles were selected. These are Weshawushign, Dibute, Bakilo (highland), Goshe Bado (midland), and Kasima (lowland) (Figure 1).

2.4. Selection of Informants

A total of 80 informants were selected for ethnobotanical data collection from each study site. Of which, 60 (46 men and 14 women) were nontraditional healers, whereas 20 (16 men and 4 women) were traditional healers. Informants were selected randomly, while traditional healers were selected purposefully and considered as key informants. As pointed out by [19], the selection of key informants is commonly purposive. The age of the informants included in the study ranged from 25 to 70. About 31 informants were aged 56–70, which accounted for 29% followed by 41–55 accounting for 27 (34%), and 27% of informants were aged 25–40. The educational levels of the informants were from illiteracy to college level. Most of the informants were illiterate (53, 66%) followed by elementary school (20, 25%). High school and college-level education accounted for 6% and 3%, respectively.

The selection of key informants was based on the recommendations of knowledgeable elders, religious leaders, kebele administrators, literate people, and personal observations of the researcher from the community group. After that, the key informants were identified, later on, interviewed, and followed for further detail. The selection of key informants was made by asking different questions to traditional herbalists who gave different medicines for human and animal ailments.

2.5. Ethnobotanical Data Collection

Ethnobotanical data collection was conducted from February 20 to April 30, 2020, to collect information from the informants. A semi-structured interview was the main data collection tool used during the study. A list of questions based on the objective of the study was prepared in English and translated into Amharic local language of the study area. During the interview, information on vernacular name of the medicinal plants, type of disease treated, parts of the plant used, methods of preparation, mode of administration, conservation practices, and use other than medicinal value was recorded. In addition to semi-structured interviews, data were collected through group discussions and guided field walks with key informants for field observations.

The discussion was conducted with 5 to 10 key informants, mainly focusing on threats to medicinal plants, methods of conservation, and how knowledge is maintained and transferred from one generation to another generation (Figure 3).

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Figure 3

Group discussion with key informants about existing threats to medicinal plants.

Field observation with interviews was also conducted in both the wild and the home gardens of the study sites to collect the voucher specimens (Figure 4).

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Figure 4

Field observation with the guidance of local people in Basona Werana District.

2.6. Specimen Collection and Identification

Medicinal plants were collected (from wild and cultivated areas), pressed, and dried for identification. For some species, preliminary identification was conducted in the field. In addition, further identification was done using various volumes of the flora of Ethiopia and Eritrea. After that, the specimens were taken to Madda Walabu University Mini Herbarium.

3.2. Growth Form and Plant Parts Used to Treat Diseases

Herbs are represented by 33 species (43.4%), shrubs by 30 species (39.4%), and trees by ten species (13.1%), according to the growth form analysis of medicinal plants (Figure 6).

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Figure 6

Life forms of medicinal plants collected from Basona Werana District.

The informants in the study area stated that leaves were the most commonly used plant part for remedy preparation in the study area, accounting for 53 (47.3%) preparations, followed by roots and seeds, which accounted for 19 (16.9%) and 10 (8.9%) preparations, respectively (Figure 7).

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Figure 7

Plant parts used in traditional medicine preparation.

3.3. Preparation Methods, Condition, and Route of Administration of Traditional Medicine

Crushing was the most common type of traditional medicinal plant preparation, accounting for 38 preparations (33.9%), followed by pounding (18 preparations, 16%) and powdering (11 preparations, 9.8%), respectively. The remaining traditional medicinal preparation methods were organized as others, which accounted for 28% (Table 2).

Local communities in the study area employ medicinal plants in fresh, dried, and fresh or dried forms to make traditional herbal preparations. Fresh forms of medicinal plants were reported to be utilized the most (69.9%), followed by dried forms (17%) and fresh and dried forms (13.1%), respectively.

Traditional medicine is usually administered orally in the study area. Oral accounts for 54 (48.1%) of the total, with dermal accounting for 38 (33.9%) and nasal accounting for 9 (8%) of the total (Figure 8).

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Figure 8

Route of administration of traditional medicine in the study area.

3.4. Dosage and Antidote

Most traditional healers have utilized spoons, coffee cups, and tea glasses in the study area and have inserted their fingers into those tools to guess the necessary dosage. Counting the parts of the plants they used is one of the other approaches. The treatment is usually taken several times until the ailment is cured. Some traditional medicine preparations have been documented to produce diarrhoea and vomiting as side effects. Traditional healers give antidotes for patients to counteract these negative effects. Milk, honey, coffee, and tella (local beer) were given to counteract the overdose effect.

3.5. Ranking of Medicinal Plants

Ten traditional healers participated in the preference ranking, and Cucumis ficifolius stood first as it is the best preferred medicinal plant used to treat stomachache followed by Achyranthes aspera L. and Cymbopogon citratus (DC.) Stapf., respectively. Artemisia abyssinica Sch. Bip. ex A. Rich. was the least preferred medicinal plant for the treatment of stomachache (Table 3).

3.6. Direct Matrix Ranking

Based on the information gathered from the informants, six multipurpose plant species were selected randomly listed as all medicinal plants and the key informants assessed their relative importance used in their localities. With a score of 17 and 11 points, Croton macrostachyus Hochst. ex Del. was found to be the most versatile traditional medicinal plant, while Citrus x limon (L.) Burm F. was found to be the least multipurpose traditional medicinal plant (Table 4).

3.7. Informant Consensus Factor (ICF)

In the study area, a total of 54 different types of diseases were found and categorized into eight different groups (Table 5). Dermatological disease (0.78) was the category with the highest ICF value, followed by gastrointestinal tract disease (0.77). In dermatological disease, most plant species (35 plant species) were employed. For instance, A. sativum, R. chalepensis, C. abyssinica, and C. citratus were frequently reported for use in respiratory organ-related disease, stomachache, and dermatological diseases (Figure 9).

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Figure 9

Frequently used medicinal plants for various disease treatments. (a) C. citratus. (b) A. sativum. (c) R. chalepensis. (d) C. abyssinica.

3.8. Threats to Medicinal Plants in the Study Area

According to informants, medicinal plants are primarily threatened by human activity. Agricultural expansion, firewood collection, and charcoal production are the most threatening factors for medicinal plants in the study area (Table 6). Currently, medicinal plants are not easy to harvest and traditional healers have to travel long distances to collect them. H. abyssinica (Bruce ex Steud.) J.F. Gmel. and C. africana are being harvested for timber production; and O. europaea subsp. cuspidata, O. rochetiana, O. lanceolata, and C. spinarum for charcoal and firewood.

4.2. Growth Forms and Plant Parts Used for the Preparation of Traditional Medicine

Herbaceous species accounted for 33 (43.4%) of the therapeutic plants collected in the Basona Werana District. This may be due to the fact that herbs are more readily available and plentiful in the surrounding areas than shrubs and trees [18]. This result is consistent with the general trend of herbaceous species dominance found in numerous ethnobotanical studies conducted in Ethiopia [4, 8, 16, 18, 30, 31]. In contrast to the present finding, shrubs or trees were the dominant life forms as a contributor of medicinal plants in other findings [11, 17, 28, 32]. The predominance of shrubs or trees over other forms of growth may be due to their annual availability and their relative ability to withstand drought, which may be useful for widespread use [33].

Local people of Basona Werana District used various plant parts for the preparation of traditional medicine. This study indicated that leaves were the most commonly used part of the plant. Similar studies list leaves and roots as the most common parts of plants used to prepare medicines. The studies that reported the leaves as the most utilized plant parts are [5, 8, 12, 30, 32]. The studies that reported the dominance of roots over other plant parts are [24, 28, 34]. Leaves are preferred over other plant parts due to their ease of availability and ease of medication preparation. Furthermore, secondary metabolite storage is beneficial to the medicinal plant's biological characteristics [5]. Because roots and bark take longer to recover than leaves, harvesting them enhances a plant's vulnerability [35].

4.3. Preparation Methods, Condition, and Route of Administration of Remedies

Crushing is the most common preparation method in the study area. Crushing as the most common type of preparation is also reported by [8, 18, 28] in different parts of Ethiopia. However, in a similar study on people of Yilmana Densa and Quarit districts, [16] reported that splicing was a dominant method of preparation of remedy. Pounding was the dominant method of traditional medicine preparation by local people of Melokoza District [11]. Most of the remedies from dried parts were prepared by pounding, while the remedies from freshly harvested parts were prepared by crushing [16].

The majority of medicinal plants (69.9%) were found to be used in fresh form in this study. Kassa et al. [9, 18, 36, 37] all reported using freshly collected plant parts for traditional medicine preparation. People's reliance on fresh plant parts is frequently owing to the efficacy of fresh plant species in therapy, as the components are not lost before application, as is the case with dried plant forms [5]. Because local people took limited efforts in conserving dried plant matter, a frequent gathering of fresh plant parts may endanger the plants, especially during dry seasons. The dependency of peoples on fresh plant parts is often due to the effectiveness of fresh plant species in therapy as the ingredients are not lost before practice related to the dried plant forms [5]. Using fresh plant parts can threaten plants by frequent collection, even in the dry season, as locals minimize efforts to store dried plant material for later use [4, 9].

In Basona Werana District, traditional medicine is usually administered orally, which accounts for 48.1% of the total. In similar studies, other researchers reported oral administration as the leading route of application of traditional medicine [8, 17, 30].

4.4. Dosage Determination and Antidotes

Local communities use different methods to determine the dose. Spoons, coffee cups, tea glasses, and inserting a finger and counting the parts of the plants are among the approaches used to determine the dosage. This finding is consistent with the report of [9]. A lack of consistency regarding the dosage of medicines to be used was observed among the informants during the interview. It was reported that the lack of precise dosage is one drawback of traditional medicinal plants [38]. Lack of precise dosage will have an impact on the patient as taking overdosage may have many side effects. When such things happen, local healers counteract the side effects by giving milk. A similar finding was reported by [9].

4.5. Ranking of Medicinal Plants

The study revealed that all medicinal plants are not equally important for treating ailments. Local communities prefer one over another mainly based on efficacy and availability. In the preference ranking, C. ficifolius was the most preferred and ranked medicinal plants used to treat stomachache. In a similar study conducted in Sheka Zone of Ethiopia [9], C. macrostachyus was reported to be the most preferred medicinal plant against gastrointestinal problems. Similar finding for Hawassa Zuria showed that the most preferred medicinal plant reported to treat abdominal stomachache was Eucalyptus globulus [36]. A. sativum and Z. officinale were the most preferred medicinal plants for treating common colds in humans [39]. The various findings in different parts of Ethiopia indicate that local communities in their locality have their own preferred medicinal plants against different human and livestock ailments.

The direct matrix ranking indicated that C. macrostachyus and C. africana ranked first and second in the study area as a multipurpose plant species, respectively. C. macrostachyus was reported to be used mainly as medicine, firewood, and fencing. On the other hand, C. africana reported mainly for its use in construction and furniture. A various groups of researchers in Ethiopia reported different medicinal plants as a multipurpose plant species. For instance, [36] reported as Ensete ventricosum (Welw.) Cheesman was the most preferred medicinal plant used for various purposes by the local people of Hawassa Zuria District. The authors also reported that the plant was used as a type of food, as fodder, in house construction, and for making of a robe. In a similar study, [12] reported that Warburgia ugandensis Sprague was used by Guji Oromo of Ethiopia for multiple purposes such as charcoal production, for construction, and furniture. In other studies, conducted in Adwa District of Tigray Region, O. europaea subsp. cuspidata are regarded as multipurpose plant species mainly used for charcoal production, construction, and as a food [40]. The most commonly used plants are most threatened in the absence of proper conservation, management, and sustainable use measures [9]. Hence, additional conservation measures are urgently needed to prevent the disappearance of these multipurpose plant species [40].

The authors would like to thank the administrative offices of the Basona Werana District and the agricultural development organization for supplying us with useful information during the data collection process. Their gratitude also goes out to the informants who volunteered their expertise in medicinal plants and were gracious during the interview process. Mr. Mola, who assisted throughout the fieldwork, is also due with thanks. The authors are also grateful to Madda Walabu University for financially supporting the study. This study was supported by Madda Walabu University Research and community services.