An Ethnobotanical Study of Medicinal Plants in Amaya District, South West Shewa Zone of Oromia Regional State, Ethiopia

The purpose of the study was to identify medicinal plants and document associated indigenous knowledge of the Amaya District’s people related to differentiating the parts of medicinal plants, and their modes of preparation and administration to treat human and livestock diseases in South West Ethiopia. A total of 112 medicinal plant species belonging to 96 genera and 56 families were identied and documented. Most of the medicinal plants harvested were herbs followed by trees. Leaves were the most frequently used medicinal plant parts, followed by seeds and roots to prepare traditional remedies. Pounding was the most widely used mode of preparation in the study area, followed by crushing and chewing. The most commonly used route of administration was oral. The majority of medicinal plants were used in fresh condition to treat diseases. A Pearson correlation test indicated a signicant difference between age of informants and number of medicinal plant species cited, and between level of education and number of medicinal plant species cited in the District. Ocimum lamiifolium specie was cited by the highest proportion of informants, and ranked rst in treating febrile illness human disease in the study area. Malaria disease category scored the highest number of informant consensus factor value. Acmella caulirhiaz ranked rst to treat tonsillitis infections. Cordia africana ranked rst as a multipurpose medicinal plant. Farm expansion, rewood collection and lack of interest of the young and learned groups towards traditional medicines were the major threats to medicinal plants. Hence, identication and documentation of the medicinal plant species and the knowledge of the local people on how to prepare and use them is so vital for preserving them. Community based cultivation in home gardens and farmlands besides conserving them in wild, where they grow, are recommended to minimize the loss of those medicinal plants.


Introduction
From ancient times, plants have been rich sources of effective and safe medicines (Russell et al., 2006). Hence, the world primary means of treating diseases and ghting infections have been based on the use of medicinal plant species (MPs). The local peoples of different localities have also advanced their own speci c knowledge on plant resource uses, management and conservation (Cotton, 1996). Such indigenous knowledge (IK) of MPs and their use by indigenous cultures are bene cial for conservation of cultural traditions and biodiversity, besides healthcare and drug development in the present and upcoming day (Tamiru et al., 2013). Accordingly, globally, about 64% of the total world population is reliant on traditional medicine (TM) for their healthcare needs (Phondani et al., 2016). Nearly 3.5 billion people in developing countries believe in the e ciency of plant remedies and use them regularly (WHO, 2003).
In Ethiopia, over 80% of the population had been relied on TMs (Bekele, 2007;Birhanu et al., 2015) for past several years. The major reasons why MPs are demanded in Ethiopia are due to culturally associated traditions, the trust of communities on medicinal values of TMs and relatively low cost in using them (Tadesse et al., 2005;Bekele, 2007). However, in the country, TM is faced with the problem of sustainability and continuity mainly due to the loss of taxa of MPs (Kelbessa et al., 1992;Asfaw Z., 2001), that is, in turn, caused by natural and anthropogenic factors ( Lulekal et al. 2008). Hence, there exists an accelerated destruction of plant resources with loss of IK. Besides, among 85 diverse ethnolinguistic Ethiopian communities, most of them are uninvestigated (Lulekal et al. 2013). Hence, documentation of the traditional uses of MPs is critical to preserve the knowledge (Teklehaymanot and Giday, 2007).
Over utilization of wild plants in the District, particularly from Tulu Roge and Gefersa forests, and the lack of knowledge about proper conservation practices also lead to the loss of biodiversity. As a result, there is a greater danger for the loss of MPs together with IK. Despite the problems are urgent and critical, there is no any ethnobotanical study conducted to document the MPs and associated IK of the people in the District.
Lack of integration of IK with modern science for continuity, and transfer of IK from elder to young generation also needs due attention. The researchers were, thus, motivated to conduct this study in the District: (1) to identify and document medicinal plants and their parts used for medicinal purpose to treat human and livestock ailments, and (2) to examine modes of preparation, application and route of administration for remedies of the local people in the study area.

Description of the Study Area
The study will be conducted in the Ameya District, which is one of the 12 districts of South West Shewa Zone of Oromia Regional State, Ethiopia ( The District is classi ed into three agro-climatic zones: 1) highlands, ranging from 2,700 m to 3,240 m; 2) midlands, ranging from 2,100 m to 2,600 m, and 3) lowlands, ranging from 1,500 m to-2000m above sea levels. The climate data were obtained from the Metrological station of the study District. Accordingly, the rainfall pattern of the study area is unimodal, where the heavy rainy season ranges from April to September, whereas the dry season extends from October 15 to March 15, but still there is intermittent rainfall in October, March and April. The maximum and minimum mean annual rainfalls of the area were 1127 mm and 8.38 mm, respectively. The highest and lowest mean temperatures were also 28.4 0 C and 12.3 0 C, recorded in February and December, respectively. The mean annual temperature and rainfall of the study area is 19.6 0 C and 1127 mm, respectively.
Regarding the populations and health services of human and livestock in the study area also described brie y here. Accordingly, the total populations of the Amaya districts in 2018 were 122,056 (61.578 males and 60.478 females), out of the total population 5.13% is urban dweller (CSA, 2007 (Martin, 1995;Cotton, 1996). Accordingly, structured and semi-structured interviews, focus group discussions, and guided eld walks with informants were employed to obtain IK of the local people on health, plant parts used, mode of preparation, applications, and route of administration.
Structured and semi-structured interviews were conducted with both household respondents and key informants, respectively, based on the items prepared beforehand in English, and translated to local language,

Preference Ranking
Preference ranking was conducted to rank some selected MPs based on degree of their effectiveness in treating a particular disease. Following the methods of Martin (1995), key informants was asked to think order and rank the MPs based on their personal preference, community importance, or any other criteria set by him /her, and this help to indicate the most effective MPs used by the community to treat disease.

Paired comparison
Paired comparison was conducted for evaluating the degree of preference or levels of importance of selected plants. This method used to nd out the e cacy and popularity of MPs species used to treat disease following the procedure described by Martin (1995). Key informants were showed their responses independently for paired of MPs that was noted for treating diseases. A list of the paired of selected MPs with all possible combinations was made and sequence of the pairs and order within each pairs was randomized before every pair is presented to select key informants. Then, their response was recorded. The total value summed and the ranks were made on the total score of the key informants. Accordingly, the plant that gets the highest score was the most popular for treating the ailments.

Direct matrix ranking
Direct matrix ranking was conducted in order to compare multipurpose MPs commonly reported by informants following Cotton (1996). Based on the relative bene ts obtained from each MPs, multipurpose MPs species were selected out of the total MPs, and use diversities of these plants were also listed. Key informants were chosen to assign use values to each attribute (5 = best, 4 = very good, 3 = good, 2 = less used, 1 = least used and 0 = not used). Based on information gathered from key informants, average value of each use-diversity for a species was taken and the values of each species was summed up and ranked.

Characteristics of Sample Respondents
In order to represent the whole agro-climatic zones of the Amaya District, sample respondents (70) were selected from ve sample Kebeles (14 respondents from each), which are distributed in three agro-climatic zones: highland, midland, and lowland of the District. Regarding the ages of the respondents, most of them had above 40 years old (~ 63%). This shows as the ages of the respondents increase, they become more knowledgeable due to the experience they gain in their life. This was also reported by other authors (Lulekal et al. 2008(Lulekal et al. , 2013).

Composition and Growth Form of Medicinal Plants in Amaya District
A total of 112 MP species belonging to 96 genera and 54 families were identi ed in study the area (Appendix 1). With regard to plant family, Fabaceae and Asteraceae were the most popular to the area and, both were represented by nine species (8.03%), followed by Solanaceae with eight species (7.145%); Lamiaceae, seven species (6.25%), and Euphorbiaceae, six species ( Regarding their growth forms, among 112 MPs recorded from the study area, the highest representation was for herbs (51 species, 45.5%), followed by trees (25, 28.57%), and shrubs (5, 22%). The least was liana (4 species, 3.57%) (Fig. 2). This could be related to the fact that these species exhibit high level of richness and easy to obtain them, because herbs form of MPs easily available in home garden and forest patches. This nding agrees with previous studies conducted by Awas

Habitat of MPs
As depicted in Fig. 3, of the total, 65 species (58.03%) were collected from wild alone; 27 species (24%), from both home garden and wild; 11 species (9.82%), from home garden alone and nine species (8.03%), from farmland. This nding shows that local people in study area mostly depended on wild sources than home . Leaf parts (37 species) of MPs were the most frequently reported to be used in study area, followed by seeds (15 species) (Fig. 4). This is a good practice and even be promoted as a more sustainable method because leaves are many per tree so that using leaf parts rather than the other parts (particularly the root, including the bark, stem parts) of the MPs may not have signi cant impacts on the survival of the mother plants, whereas using the root parts of the MPs through uprooting of the whole plants is causing total death of the mother MPs. In fact, excessive use of leaves also has negative effect on survival and regeneration of MPs, but not as such serious as that of damaging the root, bulb, stem and bark parts used. Many authors (Amenul, 2007;Etana, 2010; Yineger and Yewhalaw, 2007) also con rmed that leaf parts of MPs mostly used for TM preparation. In Amaya District, different modes of preparation (Appendix 2) were used to treat human and livestock aliments. As depicted in Fig. 5, the major modes of preparation were pounding (30 species), crushing (29 species), pounding and ltering (20 species). This indicated that the people of the study area uses different ways of preparation and application methods based on the types of diseases treated and the actual site of ailments. The majority of the preparations were made from the mixtures of different plant species with water and different additive substances. This is similar with the work of Amenul (2007), who reported that most of the preparation was done by pounding.

Application of medicinal plants for remedies (routes of administration)
The prepared traditional medicines are applied in a number of methods. Hence, based on the report of the respondents of the study area, the major routes of administration used were oral only (36), dermal only (28), oral and dermal (19), nasal only (7), anal (3), nasal and oral (3) (Fig. 6). This result indicated that both oral and dermal routes permit quick physiological reaction of the prepared medicines with the pathogens; thereby   Fig. 7 and Appendix 2, the preparation of the MPs identi ed for remedies in the study area were in fresh (76 species), dry (23 species) and fresh or dry (8 species) conditions. This nding showed that most of the species are prepared for remedies in their fresh conditions. The frequent use of freshly processed remedies could also imply the accessibility of MPs in the locality and their high curative power while preparing in fresh conditions. This nding is also similar with other many authors' reports (e.g., Yineger In the study area, to determine the dosage, different units of measurements and the duration of administration are used. In fact, there is no uniformity with regard to the dosage of the medicine between the different traditional healers and local people (use by themselves) for same disease, although all the traditional healers and local people agree on the point that the dosage given for patients vary with age and physical strength. They do also agree that some medicines are not allowed to be taken by women when pregnant. In general, the dosages of TM to be administered for certain duration were given by estimating the age, physical strength of the patient and the severity of the diseases. Accordingly, as reported by the respondents, the amounts to be administered were estimated by the use of measurements such as length of a nger (for bark, root and stem), coffee and/or tea cup (for powdered plant material) and number count (for sap/latex drops, leaves, seeds, fruits and bulbs). Recovery from the disease, which usually is determined by the disappearance of disease symptoms, is a criterion that the local people of the study area consider to determine the duration of using the medicine. Lack of precision and standardization is, therefore, the major drawback in practicing MPs for treatments of human and livestock aliments, which are also reported by other ethnobotanical studies carried out in Ethiopia (Lulekal E. et al., 2008; Balemie and Mahamat Seid, 2014).

Marketed Medicinal plants
As depicted in Table 1, market survey results obtained from Gindoo and Qotaa markets indicated that MPs sold at market were not widely used for medicinal values, rather for other purposes. This shows that the local people prefer either immediately to collect these plants by themselves from the available area in the District so as to prepare traditional medicine or directly go to traditional healer in order to get treatments instead of buying the MPs from the market. This nding is also reported by Giday   The relationship of the knowledge of respondents on MPs corresponding to their age was illustrated in Fig. 8. In Amaya District, MPs which were popular due to the wide range of diseases they treat and commonly used are well known by the local peoples and traditional healers. Certain species were independently cited by many of the informants for their medicinal uses to treat human and livestock ailments. The results of the study showed that some MPs were popular than others. Accordingly, the highest informant consensus goes to Ocimum lamiifolium, which was cited by 32 informants (45.71%), followed by Allium sativum (38.57%), Linum usitatissimum (34.28%), Croton macrostachyus (28.57%), Citrus limon (27.14), Aloe kefaensis (25.35) and others as displayed in Table 2. The popularity of Ocimum lamiifolium was due to the preference of the species for treating febrile illness in the community rather than going to modern medication for the disease and its easy access in the home gardens of many people, as well as due to its accessibility, everybody had the chance to see the treatment with minimum secrecy of plants. The nding agrees with other work reported by Getaneh and Girma (2014). Diseases treated by MPs reported in the study area were grouped into different categories based on the site of occurrence of the disease, condition of the disease as well as treatment resemblance of the disease. The informant consensus factors were calculated for each category (Table 3). In this study, the informant consensus on MPs usage resulted in ICF values ranging from 0.42 to 0.87 per disease category. As shown in Table 3, the ailments Malaria scored the highest value (0.87) followed by internal and external parasitic diseases (0.83). This indicates that informants use relatively few taxa to manage speci c disease conditions as well as consistency in the use of plant species. MPs used to treat those ailments were more popular and effective to cure the ailments, and the ailments were more common than the others in the area. Low value of ICF indicates that the informants disagree on taxa to be used in the treatment within a category of illness. In this study, the lower ICF value was scored (0.42) for the category of diseases like sensor organ related diseases. This category may be indicative for lack of consistency in the use of MPs in study area.

Preference ranking of human disease
When there are different species prescribed for the same health problem, people show preference of one over the other. Preference ranking of seven MPs that were reported for treating febrile illness human disease was conducted after selecting 10 key informants separately. Febrile illness was most frequently reported human disease in the study area. The key informants were asked to compare the given MPs based on their e cacy, and to give the highest number (7) for the MPs which they believed most effective in treating febrile illness and the lowest number (1) for the least effective MPs in treating febrile illness. Accordingly, as presented in Table 4, Ocimum lamiifolium and Croton macrostachyus were stood the 1st and 2nd preferences of the informants, respectively, to treat the febrile illness, whereas Solanecio gigas was the least preference of them. This indicated that Ocimum lamiifolium were most effective in treating febrile illness. Similar nding was reported by Kassa et al. (2016) as Ocimum lamiifolium ranked rst to treat fever human disease in Tulu Korma and its surroundings in Ejere District, Western Shewa Zone of Oromia Regional State.

Pairwise comparison
In this study, ten key informants were selected to indicate the e cacy and popularity of the six MPs, reported to treat Tonsillitis infections so that pairwise comparison was done for those species. Accordingly, Acmella caulirhiza (52) ranked rst followed by Solanum incanum (46), Zingiber o cinale (40) and Allium sativum (29) as shown in Table 5. This indicated that Acmella caulirhiza was the most e cient MPs in treating Tonsillitis infections, whereas Vernonia amygdalina and Citrus limon were the least preferred and e cient when compared to the others. In this study area, the majority of the people rely on wild plants for various purposes such as construction, charcoal, rewood, furniture, and fencing besides medicine. To evaluate the relative importance and check the major impact on such multipurpose plants, direct matrix ranking was performed. In the area, a number of MPs were found to be multipurpose species being utilized for a variety of uses. Seven most reported multipurpose species and six use categories were involved in direct matrix ranking with 10 key informants, who were requested to give value, from 5 to the most used plants for particular purposes, up to 0 (zero) to the least ones. Respondents evaluated the relative importance of these MPs to the local peoples and the extent of the existing threats related to their use values. The values for use reports across the selected key informants were summed up and ranked for each species.
Based on this, the results of the direct matrix ranking revealed that Cordia africana ranked rst and followed by Eucalyptus globulus, Hagenia abyssinica, Croton macrostachyus, Ficus vasta, Juniperus procera and Podocarpus falcatus, which ranked 2nd, 3rd, 4th, 5th, 6th and 7th (Table 6), respectively. Hence, Cordia Africana was the most preferred multipurpose plant and over harvested for not only medicinal purpose, but also for other uses such as furniture and construction largely. Therefore, the most preferred plant by local people for various uses, the most threatened species; which was evidently shown by its scarce distribution in the area. From this, one could conclude that the top ranked species were highly threatened as there was high rate of loss of Cordia africana in the study area. Even though the rank was given, all of the species particularly the top ranked ones are under question in their long-term survival since the livelihoods of some people in the study area directly depended on these species. This nding is in line with Teklay (2015) that Cordia africana was most preferred multipurpose plants in Kilte Awulaelo District of Tigray Regional State, Northern Ethiopia. Factors threatening MPs are caused by anthropogenic and natural causes. Based on the respondents' perception, farm expansion (cited by 20 informants) stood rst, followed by rewood and charcoal (18), and furniture (10) to be the most threatening factors to MPs in the study area. The least threatening factor was plant collection for medicine (1) (Fig. 10). This study indicated that farm expansion was found to be the highest threatening factor to MPs it might be due to increasing in population. Balemie

Conclusion
In Amaya District, several plants are used for medicinal purposes. As compared to other studies, a number of MPs and associated IK were reported to be used for human and livestock aliments in study area. Most of the MPs were used for human aliments rather than livestock aliments, and harvested from wild rather than farmlands and home gardens. Herbs were highly utilized growth forms of MPs than trees, shrubs, climbers /lianas. Leaf parts of MPs were highly harvested for remedy preparations, followed by seeds and roots. Most of the MPs were prepared by pounding their parts used, and fresh forms were mostly used in the study area.
Oral route of administration was the most commonly used ways of application. In the study area, elders have better knowledge of medicinal plant than younger, while peoples are more educated and young, they do not prefer to use MPs as their parents and grandparents did due to their modernization, un-aged, religion and absence of interest from traditional healers and elders to transfer their IK to other persons. Farm expansion, rewood and charcoal collection, furniture, drought, overgrazing, over harvesting for food and spices, construction, introduction of exotic plants, application of pesticide and herbicide, and use for medicine were the major threatening factors to MPs in the study area. Local peoples were practicing ex-situ and in-situ conservation approaches for decreasing loss of MPs from the study area. Plantation of MPs, seed and bulb storage, and restricting grazing by livestock were the major efforts of the local people along with the support of the government to conserve plants in their natural habitats.  Figure 1 A map illustrating the study District in Oromia Regional State, Ethiopia. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.

Figure 1
A map illustrating the study District in Oromia Regional State, Ethiopia. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.

Figure 2
Growth form of MPs in the study area  Habitats of MPs in the study area Habitats of MPs in the study area Condition of preparation of medicine to treat human and livestock in the study area