Journal of Botany
Volume 2017 (2017), Article ID 8383468, 10 pages
https://doi.org/10.1155/2017/8383468

Research Article

Study on the Diversity and Use of Wild Edible Plants in Bullen District Northwest Ethiopia

Tariku Berihun¹ and Eyayu Molla²

¹Department of Biology, Dilla University, P.O. Box 419, Dilla, Ethiopia
²Department of Biology, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia

Correspondence should be addressed to Tariku Berihun; berihun.tariku@yahoo.com

Received 9 January 2017; Accepted 16 April 2017; Published 15 May 2017

Academic Editor: Muhammad Iqbal

Copyright © 2017 Tariku Berihun and Eyayu Molla. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

This study was designed to document the use and conservation of wild edible plants in Bullen district, northwestern Ethiopia. Data was collected through semistructured interview and focus group discussions. The collected data was analyzed through direct matrix ranking, pairwise ranking, and priority ranking methods. In this study, a total of 77 wild edible plant species were identified. Of these plants, trees account for 35.5% followed by shrubs (31.1%). Fruits were the most harvested parts (59.7%) followed by leaves (12.9%), roots and tubers (3.8%), and rhizomes (2.5%). These plants are consumed either raw (57.1%) and/or cooked (17%); most are collected by women (62.5%) and children (20.8%), but the participation of men is stumpy (4.2%). According to pairwise ranking analysis, fruits of Vitex doniana and the leaves of Portulaca quadrifida are the most preferred plant species because of their sweet taste. However, some of the plants have side effects causing abdominal pain, diarrhea, and constipation. Although religion and cultural norms and values play an important role in the conservation of wild edible plants, population pressure and its associated impacts contributed much to the disappearance of these plants. Thus, community participation is the suggested solution for the conservation and sustainable use of the wild edible plants in the study area.

1. Background and Justification

The rural communities of developing countries depend on wild edible plants to meet their food requirements during periods of food shortage. Studies conducted by [1] indicated that the wild edible plants are mostly serving as supplementary foods in different parts of Africa. Wild edible plants are nutritionally rich [2] and can supplement especially vitamins and micronutrients [3]. These show that wild edible plants are essential components of many African diets, especially in period of seasonal food shortage.

The Ethiopian flora has approximately 6000 species of higher plants of which about 10% are endemic [4, 5]. The country is known as the biodiversity hotspot and center of origin and diversification for a significant number of food plants and their wild relatives [6]. The wide range of climatic and edaphic conditions permitted the growing of a variety of wild food plants [7].

Some studies in Ethiopia indicated that many rural people are endowed with deep knowledge on how to use plant resources. This is particularly true with regard to the use of medicinal plants [8] and wild edible plants that are consumed at times of famine and other hardships [3]. In this regard, the elder community members are mostly the key sources of knowledge about plants [3].

The consumption of wild plants seems more common in food insecure areas of the country as compared to relatively food sufficient areas [9]. Thus, many rural people of Ethiopia usually feed on wild food plants for survival during food shortage [10]. Although wild edible plants play an important role during periods of food shortage, little attention has been given to conservation of wild edible plant species.

Available published studies on the ethnobotany of wild food plants are limited to specific area [11]. In northwestern Ethiopia, the consumption of wild food plants seems to be one of the important local survival strategies and appears to have intensified due to the repeated climatic shocks hampering agricultural production and leading to food shortages [2]. In Bullen district of Benshanguel-Gumez region, the noncultivated plants provide considerable amount of supplementary food and have significant contribution to generating additional income for many households. However, there has not been sufficient research carried out about the indigenous knowledge of wild edible plants in Bullen district. Therefore, this study was designed to (1) identify and document wild edible plant species, (2) identify and record the parts of wild edible plants which are edible to humans, (3) evaluate the exploitation and conservation status of wild edible plants, and (4) assess threats on the wild edible plant species and recommend the possible management scenarios for their conservation.

2. Materials and Methods

2.1. Description of Study Area

Bullen district, the study area, is located in northwestern Ethiopia lying within 10°00′ to 11°07′ N and 35°45′ and 36°07′ E (Figure 1). The altitude varies from 900 to 2300 m.a.s.l. According to the traditional agroecological zonation of Ethiopia, 85% is Kola (lowlands, warm), 10% Woina dega (mid-altitude moist, cool), and 5% Dega (highland, cool). The mean annual rainfall of the district ranges from 700 to 1000 mm. The average annual temperature ranges from 23.5 to 35.5°C. Diverse soil types exist in the areas, of which Acrisols and Nitisols that occur on the gentler slopes and Vertisols in the valley bottoms are the dominant ones [12].

Figure 1: Location map of the study area (Woreda is an administrative unit almost equivalent to a district and kebele to village).

2.2. Methodology

2.2.1. Reconnaissance Survey and Site Selection

A reconnaissance survey was conducted from August 10 to 25, 2010, to depict the different vegetation types, natural resource management, and indigenous knowledge associated with the use of wild edible plant species. Following the survey, focus group discussion was carried out in one of the study sites. After the discussion, five villages were systematically selected as study sites out of the total 15 villages of the district (Figure 1). The study villages were chosen based on proximity to the existing remnant forest resources and representativeness of the different agroecologies.

2.2.2. Ethnobotanical Data Collection

Seventy-two informants (40 males and 32 females) from different age groups were chosen from five villages of the study site based on the recommendations given from elders, Development Agents (DAs), and kebele (village) administration leaders. The ages of the informants were between 15 years and 60 years. The key informants were chosen based on traditional knowledge of wild edible plants following the suggestion made by [13]. Semistructured interviews, field observation, and focus group discussions (FGDs) were employed for data collection. Focus group discussions were employed for wild edible plants investigation to help in comparison of patterns evident among individual interviews and to reject contradictory information. Accordingly, FGDs were undertaken in groups consisting of six to eight people in five selected kebeles. Interviews were conducted in “Shinashegna, Gumuzegna, and Amharic” languages with the help of local translators.

2.2.3. Plant Specimen Collection and Identification

Based on the ethnobotanical information obtained from informants, specimens with their vernacular names were collected, numbered, pressed, and dried for identification. Preliminary identification was done in the field based on published guides of useful trees and shrubs of Ethiopia [4]. The identification was done mainly based on the works of [4, 14–16]. All voucher specimens of the wild edible plants labeled with scientific and vernacular names were stored in Biology department herbarium, Bahir Dar University.

2.3. Data Analysis

Descriptive statistics that are percentage and frequency were used to analyze the ethnobotanical data of the reported wild edible plants and their associated indigenous knowledge. Preference ranking was computed to assess the degree of preference of wild edible fruit and leafy vegetables based on taste, edibility quality, and importance of species at different seasons. Priority ranking was employed to determine threats of wild edible plants based on their level of destructive effects. To recognize threats of wild edible plant species, values from 1–5 were given: 1 is the least destructive threat and 5 is the most destructive threat. Use diversity ranking was carried out to identify the multipurpose use of wild edible plants which were commonly reported by the key informants.

3. Results and Discussions

3.1. Indigenous Knowledge (IK) Transfer and Practice

Out of the 72 respondents, 70 (93.5%) reported that their knowledge of wild food plants was acquired through observation, imitation, and oral history, while 2 (26.5%) reported that they acquired knowledge secretly from elders, when they became very old. Moreover, the respondents reported that the knowledge of wild food plants was transferred through songs, folklore, and riddles in local languages at different times especially when the people are at rest especially during the night time.

3.2. Taxonomic Diversity

A total of 77 wild edible plant species belonging to 61 genera and 39 families were recorded in the study area (Table 1). The relative high number of wild edible plants in the study area may be due to the more intensive utilization of plants by the local communities and diverse agroecology. Of the reported 39 families, Tiliaceae, Euphorbiaceae, and Moraceae had the highest number of species (5, 4, and 4), respectively. But the remaining families were represented by 1 to 3 species. The reported plant species were comparable with those reported elsewhere in Ethiopia [5, 7, 17].

Table 1: List of the reported wild edible plants in study area based on family name, scientific name, local name, habit, part used, and mode of consumption and preparation. Growth habit: T = tree, H = herb, S = shrub, and C = climber local name: GU = Gumuzegna, SH = Shinashegna; habitat: WL = wood land, FL = farm land, HG = home garden, DR = dry river bed, RV = riverine forest, RS = road side, FM = forest margin, FE = fences, RC = rocky or dry forest TB = Tariku Berihun, and Co. No = collection number.

Family
Scientific names
Local name
Habit
Part used
Preparation and mode of consumption
Habitat
Co. No

Acanthaceae
Acanthus sennii Chiove
Koshosha (SH)
H
Flower nectar
Juice of flower nectars is sipped by lip
WL, FL
TB 069

Justica ladanoides Lam.
Kakim (GU)
H
Leaves
Flesh leaves are boiled and eaten
RV EL
TB 046

Justicia schimperiana Hochst. ex Nees
Dumuga (SH)
S
Flower nectar
Juice of nectars is sipped by lip
FE
TB 014

Amaranthaceae
Amaranthus caudata L.
Darka (GU)
H
Leaves & young shoot
Young leaves and shoots of plants are eaten after being cooked with Phaseolus vulgaris L.
HG, RS
TB 034

Amaranthus cruentus Thell
Lama (SH)
H
Leaves & seed
Leaves are eaten cooked and the seed is grinded and eaten when it is changed to porridge
HG, WL
TB 063

Amaranthus hybridus L.
Dahka (GU)
H
Leaves
Leaves are eaten boiled
HG, RS
TB 031

Anacardiaceae
Rhus retinorrhoea Oliv.
Kefijanga (SH)
T
Fruit
Fruit is eaten raw
WL
TB 009

Rhus vulgaris Meikle
Bakitela (SH)
S
Fruit
Fruit is eaten raw
RV, WL
TB 015

Rhus ruspolii Engle.
Qamo (SH)
T
Fruit
Fruit is soaked with straw until it is ripe and eaten raw
WL
TB 002

Annonaceae
Annona cherimola Mill
Gishita (SH)
T
Fruit
Fruit is eaten raw
WL, FE
TB 060

Annona senegalensis Pers.
Bambuta (SH)
T
Fruit
Fruit is eaten raw
WL
TB 043

Apocynaceae
Carissa spinarum (Forssk) Vahil.
Soha (GU)
S
Fruit
Fruit is eaten raw and as juice
WL, RV
TB 068

Saba comorensis (Boji.) Pichen
Fuya (SH)
C
Fruit
Fruit is eaten raw
RV
TB 050

Apiaceae
Anethum graveolens (Mill)
Lubicha (GU)
H
Leaves
Leaves are eaten raw or after being cooked with Cucurbita pepo
RS, RV
TB 045

Foeniculum vulgare (Mill)
Qushuwa (SH)
H
Leaves
Leaves are squeezed with Allium sativum L. and used as condiment
HG
TB 037

Asteraceae
Vernonia amygdalina Del
Banjaga (GU)
H
Leaves
Leaves are eaten either raw or cooked
WL DR
TB 070

Bidens pilosa L.
Tsetsega (SH)
H
Leaves
Leaves are eaten after being boiled
RS
TB 057

Araceae
Colocosa esculanta (Hochst)
Kompha (SH)
H
Tubers
The tuber is cut off, dried for one day, and eaten after being properly boiled
RV, HG
TB 004

Arecaceae
Borassus aethiopum Mart.
Goha (SH)
T
Fruit &young seedling
Germinating parts are eaten after being boiled and the fruit is eaten raw after soaking with straw for a month
WL
TB 038

Phoenix reclinata Jacq
Wola (SH)
S
Fruit and stem
External surface of the young stem is removed by sharp materials and boiled for two days until toxic substances are removed and then after staying for 30 minutes before eating. Fruit is eaten raw or after soaking with straw until it is ripened
FM, WL
TB 003

Balanitaceae
Balanites aegyptiaca (L.) Del.
Qota (SH)
T
Fruit
Fleshy exocarp of the fruit is removed first and then the stony mesocarp is broken and the endocarp fruit is roasted and is eaten after getting immersed with alcohol for sexual excitement and to neutralize the alcoholic effects
WL
TB 071

Boraginaceae
Cordia africana Lam.
Banja (SH)
T
Fruit
The fruit is eaten raw
WL, FM
TB 051

Celastraceae
Maytenus senegalensis (Lam.) Excell.
Tisha (GU)
S
Fruit
The fruit is eaten raw
WL
TB 012

Salacia congolensis (Wild.)
Tsera (SH)
S
Stem bark
The internal part of stem bark is removed carefully ground and the extracted juice is used as sauce
WL
TB 036

Commelinaceae
Commelina africana L.
Echaya (GU)
T
leaves
Leaves are eaten after cooking
WL
TB 047

Cucurbitaceae
Cucurbita pepo L.
Maximara (SH)
C
Leaves
Young leaves are eaten after cooking
HG
TB 053

Gladiolus candies (Rendle)
Engula (SH)
C
Young shoot
Young shoots are eaten after cooking
RV
TB 001

Momordica foetida Schumach.
Badha (SH)
C
Leaves and fruit
Young leaves are eaten after cooking and the fruit endocarp is eaten raw
RV
TB 028

Dioscoreaceae
Dioscorea cayenensis Lam.
Egera (GU)
C
Tubers/root
The poisonous parts of tubers are removed and the remaining parts are eaten after cooking
WL, RV
TB 010

Dioscorea prehensilis Benth
Anga (GU)
C
Root/tubers
Boiled tuber is eaten
WL
TB 040

Ebenaceae
Diospyros mespiliformis Hoechst
Maranta (SH)
T
Fruit
Fruit is eaten raw
RV, FL
TB 072

Erythroxylaceae
Erythroxylon fischeri Engle
Tiriga (GU)
H
Leaves
The leaves are eaten raw
HG
TB 030

Euphorbiaceae
Bridelia micrantha Hoechst
Yejega (GU)
T
Fruit
The fruit is eaten raw
WL, FL
TB 062

Croton macrostachyus Del.
Shekeshek (SH)
T
Leaves
Young cooked shoots eaten
WL
TB 076

Bridelia scleroneura Muell.Arg.
Ajega (GU)
T
Fruit
The fruit is eaten raw
WL, FL
TB 044

Sepium ellipticum L.
Andirgago (SH)
S
Fruit
The fruit is eaten raw
RC
TB 065

Clutia lanceolata Hoechst
Doguha (SH)
S
Fruit
The fruit is eaten raw
WL
TB 067

Fabaceae
Senna obtusifolia (L.) Irwan & Barneby
Bamdisa (GU)
H
Seed
Endocarp is eaten raw
HG, RS
TB 011

Piliostigma thonningii (Schum.) Milne-Redh
Mac’a (SH)
T
Fruit
Fruit is eaten raw
WL
TB 033

Tamarindus indica L.
Dogha (SH)
T
Fruit
Fleshy exocarp is eaten raw
WL
TB 008

Flacourtiaceae
Oncoba spinosa Forssk.
Ula (SH)
S
Fruit
Fleshy endocarp is eaten raw
WL
TB 059

Loganiaceae
Strychnos innocua Del.
Oola (SH)
T
Fruit
The fruit is eaten raw
WL, DR
TB 035

Strychnos spinosa L.
Merenza (GU)
T
Fruit
The fruit is eaten raw
WL
TB 047

Malvaceae
Abelmoschus esculentus (L.)
Andeha (GU)
H
Fruit
The fruit is eaten raw
HG
TB 024

Abelmoschus ficulneus (L.) Monch
Andha yiza (SH)
H
Fruit
The fruit is eaten raw
Hg, FM
TB 058

Hibiscus cannabinus L.
Tisha (GU)
H
Leaves
Leaves are burned until they form ash and are used as salt
HG, FL
TB 032

Moraceae
Ficus vasta Forssk
Bowa (GU)
T
Fruit
The fruit is eaten raw
RV, F
TB 021

Ficus sur Forssk
Essa (SH)
T
Fruit
The fruit is eaten raw
RV
TB 013

Ficus sycomorus L.
Fuqa (GU)
T
Fruit
The fruit is eaten raw
WL, FL
TB 067

Moras alba L.
Injor (SH)
S
Fruit
The fruit is eaten raw
FE
TB 019

Moringaceae
Moringa stenopetala Lam
Sheferwu (SH)
S
Y, L
Cooked young leaves, eaten with Phaseolus vulgaris L. and rice
HG
TB 016

Musaceae
Ensete Ventricosum (Wild)
Echecha (SH)
T
Fruit
The fruit is eaten raw
RV, HG
TB 066

Eugenia uniflora L.
Badirbonga (SH)
S
Fruit
The fruit is eaten raw
WL
TB 064

Myrtaceae
Syzygium guineense (Wild.) Dc. sp. guineense
Daguwa (GU)
T
Fruit
The fruit is eaten raw or drunk in juice form
RV
TB 061

Syzygium guineense (Wild.) Dc. ssp. macrocarpum
Diwa (SH)
T
Fruit
The fruit is eaten raw
WL, FL
TB 018

Poaceae
Oxytenanthera abyssinica (A. Rich.) Munro
Soha (GU)
H
Yse
The young seedling boiled and eaten with bread
WL, HG
TB 007

Polygonaceae
Rumex abyssinicus Jacq
Ambata (SH)
H
Root
Root grinded by mortar and the squeezed part used as food decoction
HG
TB 073

Olacaceae
Ximenia americana L.
Meyo (GU)
T
Fruit
The fruit is eaten raw
WL, FL
TB 017

Portulacaceae
Portulaca quadrifida L.
Kiwa (SH)
H
Leaves
The shoot part is ground together with Allium sativum, Foeniculum vulgare, and Ruta chalepensis toform sauce and eaten with porridge and injeria (local bread)
HG, FL
TB 006

Sapotaceae
Mimusops kummel A.DC.
Shemiya (SH)
T
Fruit
The fruit is eaten as raw
WL, FL
TB 040

Solanaceae
Lycopersicon esculentum Mill
Komidira (SH)
H
Fruit
The fruit is eaten raw
R
TB 048

Physalis peruviana L.
Bosiya (SH)
H
Fruit
The fruit is eaten raw
Rs, DA
TB 023

Solanum nigrum L.
Func’a (SH)
H
Fruit and leaves
The fruit is eaten raw and the leaves are eaten raw together with green pepper
HG, RS
TB 054

Rhamnaceae
Ziziphus abyssinica Hoechst
Anguga (GU)
T
Fruit
The fruit is eaten raw
WL
TB 055

Ziziphus spina-christi (L.) Wild
Sirah (Gu)
T
Fruit
The fruit is eaten raw
WL
TB 049

Sapindaceae
Lepisanthes senegalensis Pers
Bekuda (SH)
S
Fruit
The fruit is eaten raw
Wl
TB 052

Rubiaceae
Gardenia ternifolia Schummach &Thonn.
Gaaba (GU)
T
Fruit
The fruit is eaten raw
WL, FL
TB 016

Pavetta crassipes (K.Schum)
Munqa (SH)
S
Fruit
The fruit is eaten raw
WL, FL
TB 020

Vangueria apiculata L.
Hawa (SH)
S
Fruit
The fruit is eaten raw
FM
TB 056

Tiliaceae
Grewia bicolor Juss
Somoya (SH)
S
Fruit
The fruit is eaten raw
FE.FL
TB 074

Grewia ferruginea Hochst. ex A.Rich
Galqoriya (Sh)
S
Fruit
The fruit is eaten raw
WL
TB 039

Grewia mollis Juss
Qoriya (GU)
S
Stem bark
The inner parts of stem bark are safely removed and soaked with hot water and grinded and collecting juice used as sauce
WL, FL
TB 025

Grewia schweinfurthii Burret.
Badiriya (GU)
S
Leaves
The fruit eaten raw
RV.FL
TB 077

Corchorus olitorius L.
Laliaq (SH)
H
Leaves
Young leaves eaten raw or after being cooked
FL, DR
TB 027

Verbenaceae
Vitex doniana Sweet
Kokor (SH)
T
Fruit
The fruit is eaten
WL
TB 005

Ulmaceae
Celtis africana Brum.f.
Qawo (GU)
T
Fruit
The fruit is eaten raw
DR
TB 07

Zingiberaceae
Etlingera littoralis L.
Zingibila (GU)
H
Tuber
The fruit is eaten raw
RV
TB 026

3.3. Growth Forms, Parts Used, and Mode of Consumption/Preparation

The largest numbers of edible wild plant species were found to be trees, followed by herbs, shrubs, and climbers (Figure 2). This result also concurs with the works of [17, 18]. Regarding parts used, a total of 6 edible parts were recorded. Of these, 63.6% were fruits, 20.8% leaves, and 6.5% roots and tubers, while the remaining 9.1% were flowers, nectar, stem barks, and seeds (Figure 3). This implies that more than one part of a plant species was consumed by humans. The result concurs with [19]. As regards the mode of consumption, 57.1% are consumed raw, 16.9% boiled, 6.5% in juice form, 9.1% either raw or boiled, and 5.2% as porridge/sauce (Figure 4).

Figure 2: Number and habit of wild edible plants used by the local people.

Figure 3: Mode of consumption.

Figure 4: Number of wild edible plant parts used by the local people. FO = fruit only, Lo = leaf only, FL & Ne = flower and nectars, SB = stem bark, RT & TU = root and tuber, and OP = other part.

3.4. Preference of Edibility of Parts

In the study area preference of wild food plants parts varied. For example, plants consumed during famine were not consumed during normal periods. As informants reported, the roots of Dioscorea cayenensis Lam. and the young stem of Phoenix reclinata Jacq. are only consumed during times of food shortage. Moreover, the results of pairwise ranking in Table 2 indicated that the fruits of Vitex dodoniaa Sweet are the most preferred wild food fruits over the other reported wild food fruits (Table 2). This is due to them being well known by all communities. Preference of wild leafy vegetables indicates that Portulaca quadrifida L. ranks first (Table 3). This is due to their easy accessibility and palatability. These results concur with [10].

Table 2: Pairwise ranking based on taste of seven edible fruits in study area.

Plant species
Respondents
Score
Rank

1
2
3
4
5
6
7

Annona senegalensis
4
5
2
3
4
5
2
25
2nd

Balanites aegyptiaca
3
2
4
2
3
1
2
17
4th

Vitex doniana
5
4
2
3
5
5
4
28
1st

Tamarindus indica
2
3
4
5
2
3
1
20
3rd

Syzygium guineense
2
1
3
4
3
1
2
16
5th

Ziziphus spina-christi
1
1
2
1
2
3
4
14
6th

Oncoba spinosa
2
3
3
2
2
1
1
13
7th

Table 3: Pairwise ranking based on taste of seven green leafy vegetables in study area.

Plant species
Respondents
Score
Rank

1
2
3
4
5
6
7

Portulaca quadrifida
4
1
4
4
5
5
1
24
1st

Corchorus olitorius
3
2
4
5
1
2
4
21
2nd

Amaranthus hybridus
1
1
1
1
2
2
3
11
6th

Solanum nigrum
4
5
1
3
3
2
2
20
3rd

Vernonia amygdalina
2
2
1
1
1
3
2
12
5th

Bidens pilosa
2
3
1
1
1
1
1
10
7th

Rumex abyssinica
3
4
2
3
1
4
4
21
4th

3.5. Traditional Medicinal and Other Uses of Wild Edible Plants

In the study area informants reported that of the identified plant species sixteen (20.7%) plant species including parts such as leaves, fruit, stem bark, root, and seeds were mentioned as useful to treat one or more human health problems (Table 4). The number of these plants against the specific human ailment ranged from 1% to 18.7%. Of the 16 species mentioned, the leaves and roots of Balanites aegyptiaca got priority by the local communities to relive abdominal pain. The fruit of Cordia africana is also mentioned as treatment for diarrhea; the leaves of Solanum nigrum are used to treat abdominal pain and the roots of Carissa spinarum for remedying tape worm.

Table 4: Traditional medicinal importance of some wild edible plants for human in the study area ().

Scientific name
Treated health problem symptom
Part used
Habit
Number of citations
Participants cited for use (%)

Balanites aegyptiaca
Abdominal pain
Leaf/root
Tree
9
18.75

Malaria
Root
1
2.08

A kind of dermal swelling
Root
1
2.08

Hypertension
Root
1
2.08

Bichawoba
Root
1
2.08

Bidens pilosa
Tanea pedis
Leaf
Herb
1
2.08

Amaranthus hybridus
Tape worm
Leaf
Herb
12
25

Carissa spinarum
Tape worm
Root
Shrub
3
6.25

Constipation
Fruit
1
2.08

Gonorrhea
Fruit
3
6.25

Cordia africana
Diarrhea
Fruit
Tree
10
20.8

Constipation
Fruit
2
4.1

Abdominal ache
Fruit
1
2.08

Corchorus olitorius
Diarrhea
Leaf
Herb
1
2.08

Grewia bicolor
Venereal disease (syphilis)
Fruit
Shrub
2
4.1

Constipation
Root
1
2.08

Gardenia ternifolia
Liver disease
Root
Shrub
1
2.08

Abdominal ache (coli)
Root
2
4.1

Abdominal distension
Root
1
2.08

Momordica foetida
Bronchitis
Leaf
climber
1
2.08

Ficus sur
Ring worm
Sap
Tree
1
2.08

Portulaca quadrifida
Diarrhea
Aerial part
Herb
4
8.3

Abdominal distension
Aerial part
1
2.08

Abdominal ache coli
Aerial part
1
2.08

Vernonia amygdalina
Abdominal pain
Leaf
Herb
2
4.1

Solanum nigrum
Abdominal pain
Leaf
Herb
3
6.25

Malaria
Leaf
1
2.08

Tamarindus indica
Abdominal pain
Fruit
Tree
1
2.08

Ximenia americana
Abdominal pain
Fruit
Tree
1
2.08

Gastritis
Fruit
1
2.08

Wound (as ointment)
Fruit
1
2.08

Ziziphus abyssinica
Diarrhea
Root
Shrub
1
2.08

Abdominal pan
Root
1
2.08

Note. Based on growth habit, the total number of medicinal wild edible plants in the study area: herb = 6, tree = 5, shrub = 4, and climber = 1.

Most of the plant remedies used by the people of Bullen district are obtained from herbs (37.5%) followed by trees (31.2%) (Table 4). Data analysis showed that the majority (20.7%) of medicinal plants in the wild are herbs and are used in the treatment of different kinds of diseases, in addition to their food value. This result indicates that people rely more on herbs and trees because they are relatively common in the area compared to shrub species. This finding agrees with the findings of [17, 20] in southern Wello Chefa area and Debub Omo Zone.

The most widely sought plant parts in the preparation of remedies are roots (56.2%). The popularity of these parts has grave consequences, from both ecological point of view and the survival of the wild edible species point of view [21]. On the other hand, collecting leaves alone could not pose a lasting danger to the continuity of an individual plant compared with the collection of roots, bark, stem, or whole plant.

3.6. Multipurpose Use of Wild Edible Plants

Apart from their food and medicinal values, the reported wild edible plants are used for different purposes. Direct matrix ranking was undertaken in order to evaluate multipurpose use of tree species and their relative importance to the local people and the extent of the existing threats related to their use values (Table 5). The result of use diversity indicates that Syzygium guineense are ranked 1st because they are used for different purposes such as construction, firewood, fence, and so forth in the study area. This shows that the local people harvest the wild edible plants not only for food but mostly for construction, firewood, and furniture (Table 5).

Table 5: Average score for direct matrix ranking of the 11 wild edible plant species on eight use criteria (use given from 0 to 4, 0 = not used, 1 = least used, 2 = good, 3 = very good, 4 = excellent).

Edible plant species and ranking
Total
Rank

1
2
3
4
5
6
7
8
9
10
11

Edibility
2
0
2
1
2
1
3
1
1
3
1
17
6th

Medicine
0
4
2
0
0
3
0
1
0
0
0
10
8th

Construction/building
1
3
4
3
3
4
3
3
3
2
0
29
1th

Furniture
4
0
3
3
3
3
4
2
0
0
0
22
3rd

Agricultural tools
0
0
1
0
4
1
0
0
2
3
1
12
7th

Fuel wood collection
2
2
3
1
2
4
2
1
2
3
2
24
2nd

Fodder
2
1
1
4
3
3
1
2
0
4
0
21
4th

Fencing
0
0
4
0
4
3
3
3
0
3
0
20
5th

Total score
11
10
20
12
21
22
16
13
8
18
4

Rank
8
9
2
7
3
1
5
6
10
4
11

1 = Annona senegalensis, 2 = Carissa spinarum, 3 = Cordia africana, 4 =  Piliostigma thonningii, 5 = Ficus sur, 6 = Syzygium guineense, 7 = Vitex doniana, 8 = Ximenia americana, 9 = Ziziphus abyssinica, 10 = Balanites aegyptiaca, and 11 = Ziziphus spina-christi.

3.7. Threats to Wild Edible Plants

Currently some of the remnant forests with large numbers of the wild edible plants in the study area are subjected to frequent deforestation by the local community. This is attributed mainly to human population pressure and its associated effects. Agricultural land expansions, wild fire, fuel wood collection, overgrazing, and overharvesting are the main reasons for the destruction of wild edible plants. Of these factors, agricultural land expansion ranks first followed by overgrazing and fuel wood collection (Table 6).

Table 6: Priority ranking of threats to wild food plants used on their degree of destructive effects/values of 1–5 that were given: 1 is the least destructive threat and 5 is the most destructive threat.

Factors
Respondents of each village
Total
Rank

A1
A2
A3
Dm1
Dm2
Dm3
B1
B2
Ch1
Ch2
Ab1
Ab2

Agricultural land expansion
4
3
4
2
2
1
3
2
1
1
3
3
29
1st

Uncontrolled fire setting
1
2
1
3
1
1
3
2
1
3
2
1
21
4th

Fuel wood collection
3
2
3
2
3
2
1
2
2
1
1
2
24
3rd

Overgrazing
2
2
3
1
4
2
3
3
2
2
1
1
26
2nd

Overharvesting
2
3
1
3
1
3
0
1
1
2
0
1
18
5th

A = Aygal mozanbus; Dm = Doshna Moch; B = Bardud; Ch = Chilanqo; Ab = Azemina Banosh.

The level of threats of wild edible plants varies among the different studied villages of the district. Accordingly, informants from Aygal Mozanbus and Azemna Bansh rated agricultural land expansion as the principal threat to wild edible plant species. This is mainly due to increasing demand for arable land due to increasing human population. In the Baruda village, overgrazing uncontrolled fire setting followed by agricultural land expansion is the major factor that threatens the wild edible plants’ diversity. The introduction of new grazing land due to high livestock density has possibly resulted in the overgrazing of large areas of the Baruda village. Similarly, in Doshna Moch, informants claimed fuel wood collection to be equally hazardous as overgrazing in threatening wild edible plants species. Uncontrolled fire setting was also another major threat to wild plant in Chilanqo village. It was observed that many woody species were severely affected by such fires where the tree and shrub stands decline and some are completely burned. Others are dried and collected as fire wood and the newly grown vegetative parts of woody species are further overbrowsed and trampled by overgrazing, causing considerable damage to the species. The same result was reported by [19] in Derashe and Kucha districts of southern Ethiopia, indicating that uncontrolled fire affects many woody plants including fire tolerant species when the duration of fire is too long.

3.8. Conservation of Wild Edible Plants and Associated Knowledge

Agricultural land expansion, fuel wood collection, and uncontrolled fire setting are the major threats to the conservation of wild edible plants in the study area. Despite the understanding of the local people about the importance of conserving the wild edible plants, only some in situ (in original/natural habitat) conservation methods like planting in the form of fences and protected pasture land in different worship areas (churches, mosques) and in their farm field/farm margins are being practiced in the study area. This indicates that the necessary conservation measures are not being taken in the area, and hence the wild edible plants are not free from threats.

4. Conclusion

The knowledge of wild food plants was transferred through songs, folklore, and riddles in local languages at different times especially when the people are at rest especially during the night time. The study revealed that all household members of the study area were involved in the collection and consumption of wild edible plant species. This helps to ensure the maintenance of indigenous knowledge associated with wild edible plant species. However, there is a decline in the consumption of some wild edible plant species that were used during periods of drought and famine such as the young seedling of Borassus aethiopum and the young stem of Phoenix reclinata which gradually lead to the fade-away of the indigenous knowledge associated with them. The local knowledge about the nutritional composition and side effects of the wild edible plant species is very scanty and little is known about undesirable side effects such as toxicity originating from the wild edible plants. Apart from their food and medicinal value, most of the identified wild edible plant species in the study area are used by the community for other different purpose. The local people harvest the wild edible plants not only for food but also for construction, fire wood, and furniture. Particularly, wild edible plant species such as Syzygium guineense and Cordia africana are multipurpose plant species widely used by the local communities. Thus, this has led to a high level of threats to the wild edible plant species in the study area. In addition, many of the wild edible plants found in the study area are found to be under growing pressure, due to anthropogenic and socioeconomic factors. This has resulted in the dwindling of the species of wild edible plants and the associated indigenous knowledge.

Conflicts of Interest

The authors have not declared any conflicts of interest.

Acknowledgments

The authors are grateful to the informants and local communities of Bullen district for sharing their incredible accumulated knowledge of the wild edible plants in the field. Without their contribution, this study would have been impossible.

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