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Article

Indigenous Knowledge on the Uses and Morphological Variation among Strychnos spinosa Lam. at Oyemeni Area, KwaZulu-Natal, South Africa

by
Zoliswa Mbhele
1,
Godfrey Elijah Zharare
2,
Clement Zimudzi
3 and
Nontuthuko Rosemary Ntuli
1,*
1
Department of Botany, Faculty of Science, Agriculture and Engineering, University of Zululand, KwaDlangezwa 3886, South Africa
2
Department of Agriculture, University of Zululand, KwaDlangezwa 3886, South Africa
3
Department of Biological Sciences and Ecology, Faculty of Science, University of Zimbabwe, Harare P.O. Box MP167, Zimbabwe
*
Author to whom correspondence should be addressed.
Sustainability 2022, 14(11), 6623; https://doi.org/10.3390/su14116623
Submission received: 26 April 2022 / Revised: 24 May 2022 / Accepted: 25 May 2022 / Published: 28 May 2022
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Abstract

:
The majority of rural communities in South Africa are characterised by insufficient nutrition and food insecurity at the household level. Due to a lack of information about indigenous fruit trees and their use, food-insecure households are missing out on the nutrition that these fruits provide. Strychnos spinosa Lam. (monkey orange; umHlala) has been identified as one of southern Africa’s top priority fruit species for domestication. However, indigenous information on S. spinosa usage and morphological diversity is still lacking. Indigenous knowledge of species characteristics might be a good place to start when attempting to understand variations in key phenotypic traits. Information on the use and morphological variation of S. spinosa was collected from participants of 100 randomly selected homesteads. Participants were interviewed using a structured questionnaire. The results indicate that S. spinosa is a multi-purpose tree with numerous uses. Most respondents (97%) mentioned that they use it for fermented maize meal (umBhantshi); and others mentioned fermented porridge (amaHewu); alcohol; fruit; juice; jam; homestead protection; snakebite; firewood; food allergy; livestock increase; and only 7% mentioned for stomachache. Morphological variation was observed in leaf colour and shape, fruit rind colour, size, rind texture, pulp colour, pulp texture, and taste. However, the most mentioned variety featured green (78%), rounded leaves (78%) and green (39%), large (46%), smooth-textured rind (73%) fruits that had brown pulp (54%) and tasted sweet (58%). Understanding local knowledge systems and preferences can thus inform the selection of ethno-varieties that hold importance to local people and the potential to improve livelihoods in externally led domestication and development programs.

1. Introduction

Strychnos spinosa Lam., commonly known as monkey orange (English) and umHlala (isiZulu), is a multi-purpose plant with benefits ranging from food, medicine, fodder, magical purposes, and cultural uses [1] (Figure 1). The utilisation of indigenous plant resources for food and medicine is part of indigenous knowledge and traditions passed down through the centuries [2]. Indigenous knowledge refers to local information that is specific to a culture or civilisation [3]. This knowledge is required to be able to identify edible wild fruits and prepare indigenous foods. Previously, the usage and commercialisation of indigenous fruit trees were overlooked since certain species are poorly known, only utilised locally, and there is a lack of indigenous knowledge [4]. This lack of knowledge about indigenous fruit trees and their use has resulted in food-insecure households failing to benefit from the nutrition these foods offer [5].
Africa’s wide variety of indigenous fruit trees represents the unrealised potential for food and nutrition security [5]. Throughout human history, certain wild edible plants have played an essential role in various world geographical locations [6]. The majority of South African rural areas are characterised by insufficient nutrition and food and nutrition insecurity at the household level [7]. Indigenous fruit trees are consumed because they are easily accessible and available [5]. S. spinosa is found in only four provinces in South Africa, and this would explain the limited distribution and narrow knowledge base in terms of their uses and value. As is sometimes the case, traditional knowledge is orally transmitted from generation to generation, and it is not documented [8].
The morphological variation of S. spinosa has been recommended for study [9,10]. Identification of distinct traits is a good place to start when one studies the factors that cause variation in major phenotypic qualities [11]. Such traits are known by the local people and farmers [12]. Presently, there is a paucity of knowledge, with limited literature on several aspects of the S. spinosa fruit [5]. Studies on other tree species have shown that local people mainly recognise variability based on bark, wood, and fruit characteristics [3]. Indigenous knowledge of species characteristics might be an excellent place to start when understanding variations in key phenotypic traits. Farmers also recognise distinct locally defined taxa or classifications for a particular species based on intra-specific variations, mainly phenotypic [11].
S. spinosa has been identified as one of the most important fruit species for domestication in southern Africa [13]. Previous studies have demonstrated the species’ importance as a human food and medicine source [1,14,15,16], especially in Zimbabwe, where the fruit is processed into other nutritious food items [10]. However, due to a scarcity of information on S. spinosa’s use in South Africa, there is still a dearth of understanding that may ensure its long-term sustainability. Indigenous fruit tree uses in rural communities in South Africa have been extensively documented [5,17,18,19,20]. However, little is known about S. spinosa’s use to our knowledge, with just direct fruit consumption and no morphological diversity described in South Africa. Information on its use, local attitudes, and morphological variation on the species’ integration into agroforestry systems might be beneficial in addressing concerns about its domestication [1].
Understanding local knowledge systems and preferences can thus inform the selection, in externally led domestication and development programs, of ethno-varieties that hold importance to local people and have the potential to improve local income, livelihoods, and food security [11]. The domestication process is divided into three stages: identification of indigenous tree species and their uses, capturing germplasm by seed or vegetative propagation, and assimilation of promising species into current farming systems [12]. This study aims to document and explain the traditional uses of S. spinosa in the Oyemeni Area in KwaZulu-Natal, South Africa, and to record morphological variation in the fruit tree characteristics.

2. Materials and Methods

2.1. Study Area

The study was conducted in Oyemeni area (28°50′ S; 31°42′ E), which is in the jurisdiction of King Cetshwayo District municipality situated in the north-eastern part of KwaZulu-Natal Province in South Africa (Figure 1). This area falls under the tribal authority of Inkosi (Chief) Mzimela. Oyemeni is situated in the Ongoye hills, with an altitude that ranges from 305–490 m. The Ongoye Reserve receives an annual rainfall of between 800–1100 mm. Maximum temperatures of 37 °C are recorded in January and February, while the lowest temperatures of 8 °C are recorded in May, June, and July [21]. The area comprises a large contiguous forest patch and small peripheral forest patches, surrounded by 1072 ha of coastal climax grassland [22]. The climax forest has a continuous canopy, large trees (25–30 m), and poorly developed shrub and field levels. Orchids and epiphytic ferns are common. In the past, the Zulu royal household used to protect the Ongoye woodland because of the therapeutic significance of the plants found there [23]. The choice of site was based on the knowledge that S. spinosa grows abundantly in this area and is consumed by the local people. The species is also ranked as the most important indigenous fruit tree species in KwaZulu-Natal, South Africa [13,24]. S. spinosa is a small to medium-sized, spiny deciduous tree growing up to 10 m tall, with a trunk sometimes fluted up to 25 cm in diameter [25]. The leaves of S. spinosa are opposite and decussate, obovate with the broadest part near the apex, entire margin, and sometimes wavy, light to dark green above but paler beneath [26]. The length size of the leaves varies; small is 1–2 cm, big is 3–8 cm, and large is 3–6 cm [16]. S. spinosa fruits are classified as berries. Fruits are indehiscent, oval-shaped, green when unripe, yellow or orange coloured when ripe, with a hard pericarp [26].

2.2. Data Collection

Ethnobotanical Survey

Permission to conduct the study was obtained from the University of Zululand Research Ethics Committee (protocol code UZREC 171110-30 Dept. 2016/120). A reconnaissance field trip was conducted in September 2021 in the Oyemeni Area, KwaZulu-Natal, South Africa, to confirm the occurrence of the species, explain the goals of the research project, obtain permission to conduct this study within the area, and also to meet the relevant community leadership structures in King Cetshwayo District for prior informed consent. A letter was written to the leadership structure to obtain full access to the area and communicate with community members. The questionnaire was pilot-tested on participants from a few homesteads to test the feasibility and then validated.
Indigenous knowledge on the uses and morphological variations among S. spinosa morphotypes was collected from participants of 100 randomly selected homesteads. Only a well-informed and knowledgeable participant about the species was interviewed from each homestead. The objectives of the study were explained in the native language, isiZulu, to the interviewees. Formal surveys were conducted during the period of December 2021. Before conducting the interview, each participating individual in a homestead signed a consent form to show his/her willingness to participate in the study. Participants were interviewed using a structured questionnaire. Interviews and discussions were carried out using a local language (isiZulu) for easy communication with the participants. The questionnaire was divided into three sections: socio-demographic data, which included age (categorised as young (18–34 years), middle-aged (35–54 years), and old (55 years), and gender. Followed by morphological variance and the significance of the isiZulu term “umHlala” for S. spinosa. Information on morphological variation included leaf traits (colour and shape) and fruit traits (size, rind colour, rind texture, pulp colour, pulp texture), as well as variation in organoleptic properties, particularly in fruit taste. Lastly, local use information included the components of the plants utilised, their usage, and the method of preparation for food or medication. All questions were open-ended to facilitate a detailed explanation of the response.

2.3. Data Analysis

Among 100 participants in the study who were able to name the different uses, morphological and organoleptic variation in S. spinosa, the frequency index was calculated using a mathematical formula adapted from Mashile et al. [17].
FI = FC N × 100
where FI is the frequency index, which expresses the percentage of frequency of use or morphological variation of S. spinosa by the participant; FC is the number of participants who mentioned a use or morphological variation of S. spinosa, and N is the total number of participants.
The percentage of each gender within a specific use and morphological trait was calculated using the number of participants within the number of a specific gender divided by the total respondents per category.
  • FC: the number of participants per age group
  • N: the number of participants per gender.

3. Results

3.1. Socio-Demographic Information

A total of 100 participants were interviewed for their knowledge of the use and morphological variation of S. spinosa (umHlala) in the Oyemeni area in KwaZulu-Natal, where the majority (71%) were females, but the minority (29%) were males (Figure 2). A similar pattern was recorded among the various age groups, where more females were interviewed than males in each category. The youth had the least number of interviewed males and females compared with middle-aged and elderly interviewees.

3.2. The Significance of the isiZulu Name “umHlala” in the Context of Strychnos spinosa

All the people in the community of Oyemeni knew the direct meaning of the isiZulu name umHlala, as “to stay”. However, only a certain proportion (41%) of people understood the significance of the name. The significance of umHlala is linked to the usage of homestead protection (Figure 2). Homestead protection is a traditional ceremonial belief intended to safeguard and protect the homestead from witchcraft, sorcery, or any other evil spirits. Four unripe S. spinosa fruits are placed strategically around the homestead. It is believed that these umHlala fruits will protect people, as they have mystical properties to fight off bad spirits that may try to evict them from their homestead. The fruit is said to make a person stay safely in their homestead and work against all evil powers, hence the name umHlala—to stay.

3.3. Uses of Strychnos spinosa

(a)
Fermented maize meal (umBhantshi)
In the Oyemeni area, umBhantshi, a fermented maize meal, is a combination of maize meal and the pulp of S. spinosa. Respondents said that during preparation, the pulp is manually separated from the seeds, and the leftover seeds are discarded. The pulp is then combined with cooked maize meal (uPhuthu) or umcaba, which has been boiled and grinded). This mixture is fermented overnight and served cold with the addition of sugar, depending on the varying sweetness of the pulp. The majority (97%) of participants in the community were familiar with fermented maize meal (Table 1). Females made up most of this total (68%), with males being the minority (32%). Fermented maize meal was popular among older rather than younger women. On the contrary, younger men were more knowledgeable about this meal than older men.
(b)
Fruit
The respondents wait for the fruits to drop on the ground as a sign of ripening and then pick them up for direct consumption. Fruit selection is mostly based on fruit skin colour, fruit size, the size of the place where the peduncle was connected, pleasant scent, and juice content. After collection, the rind of the fruit is cracked open. The pulp that surrounds and is attached to the seeds necessitates the sucking of the seeds and discarding them once the pulp has been extracted. S. spinosa fruits were also popular among the community (85%) (Table 1). The knowledge on the direct consumption of S. spinosa fruits was sourced from more (72%) females than males (28%). Older ladies were more informed than younger ones among females. The youth was better knowledgeable than older men among the males.
(c)
Juice
According to the respondents, S. spinosa fruit juice is a mixture of all the fruit content and water. The rind of the fruit is broken apart, and the pulp and seeds are poured into a container filled with cold water. Depending on the sweetness of the fruit, sugar may be added. The mixture can be consumed shortly after it has been combined. Within the community, 23% of the respondents were aware of the S. spinosa fruit juice (Table 1). Knowledge of S. spinosa fruit juice was obtained mainly from females (74%) rather than males (26%). Fruit juice was the most popular among all the youth compared to other age groups in both genders.
(d)
Alcohol
According to respondents, S. spinosa alcohol is a combination of fruit juice with a little water. The juice is extracted from the fruit pulp by sieving. The seeds are discarded, and a tiny amount of water is added. The mixture is then fermented for a few days until they become ready to drink. S. spinosa alcohol was known to 7% of the respondents (Table 1). Only elderly women (71%) and middle-aged men (29%) provided information regarding this blend. All the young people, middle-aged women, and elderly males were unaware of S. spinosa alcohol.
(e)
Fermented porridge (amaHewu)
Respondents described S. spinosa fermented porridge (amaHewu) as a combination of the fruit juice and porridge. A sieve is used to separate the juice from the pulp of S. spinosa fruit. After separation, the fruit juice is then poured into newly cooked and still warm maize meal porridge. The mixture is then allowed to cool before being served. Only 6% of people knew S. spinosa fermented porridge (Table 1). The bulk of them were women (83%), and among them, the most knowledge was obtained from old women. Few men (17%) were interviewed, and information was only among elderly males in the community.
(f)
Homestead protection
Homestead protection, according to responders, is a traditional ritual belief that is aimed at securing and protecting the home against witchcraft, sorcery, or any evil spirits. Four unripe S. spinosa fruits are placed in strategic places around the homestead. This practice was known by 41% of the respondents in the community (Table 1). The practice was revealed by more females (71%) than males (29%). However, older women were more knowledgeable (66%) compared to other women. Only old men among males were informed of traditional homestead protection rituals using S. spinosa.
(g)
Snakebite
A snakebite is an injury caused by a bite from a snake. Respondents stated that an immature S. spinosa fruit is opened, and the injured person is then required to lick the bitter fruit. Twenty-four percent of those interviewed were aware that an immature S. spinosa fruit might be used to treat a snakebite (Table 1). Females (63%) made up the majority, while males (38%) made up the minority of the respondents. The majority (53%) were elderly women who were more knowledgeable. This information was only available to the minority through community elders.
(h)
Firewood
Firewood is wood that is burned as fuel. Respondents stated that dry S. spinosa wood creates an excellent fire. However, some members of the community are sceptical of the use of S. spinosa for firewood as they have a belief that if the homestead is not safeguarded by the S. spinosa fruit, lightning will strike it. Ten percent of people in the community were aware that S. spinosa wood might be used as firewood (Table 1). This knowledge was stated mostly by females (90%) than males (10%). Young and old women had the most and an equal level of knowledge (44%) across all ages’ groups in females. Middle-aged and elderly men were the only ones who had this information among men.
(i)
Food allergy
Food allergy is characterised by an unpleasant or dangerous immune system reaction following the consumption of a specific food. Respondents indicated that when a new seasonal meal is introduced, some people tend to respond badly by falling ill after eating it. In order to prevent such a response, it is necessary to boil tiny bits of the bark and drink the concussion. Only 10% of respondents in the community were aware that S. spinosa bark might be used to treat food allergies (Table 1). This information was obtained mostly from women (90%) than men. Only middle-aged males have this knowledge (10%).
(j)
Increasing livestock
Livestock refers to domestic animals, especially cattle, sheep, goats and pigs. As described by respondents, S. spinosa fruits that have developed in a cluster form are harvested off a tree with the peduncle still intact. The cluster is then buried in the centre of the kraal, and it is believed that the livestock which occupies that kraal will give birth to twins during the breeding season. A few people (7%) in the community were aware of this magical belief of increasing livestock (Table 1). Only middle-aged (71%) and elderly females (29%) held this belief.
(k)
Stomachache
Stomachache is pain from inside the abdomen or the outer muscle wall, ranging from mild to severe. Respondents said that small bits of the bark are boiled with water, and the decoction is then sipped to relieve pain. Information about this decoction was obtained from only a few (7%) community members (Table 1). Only elderly women (71%) and middle-aged males (29%) are aware of its use.

3.4. Morphological and Organoleptic Variation of Strychnos spinosa

3.4.1. Leaf Traits

(a)
Leaf colour
The leaf colour of S. spinosa leaves, which were obtained from respondents, ranged from green to dark green (Table 2). Participants mentioned more green leaves (78%) than dark green leaves (22%). Women outnumbered men among those who were questioned. Green leaves were commonly seen by middle-aged and elderly women. However, more middle-aged women (50%) and young men (43%) have identified dark green leaves compared to other age groups in each gender.
(b)
Leaf shape
The leaf form of S. spinosa varies between rounded and elongated, as described by respondents (Table 2). Round (74%) leaves were the most mentioned than the elongated (26%) leaves. This information on leaf form was largely mentioned by women than men. Older men and women were more observant of the rounded elongated than the younger men and women.

3.4.2. Fruit Traits

(a)
Rind colour
The rind of S. spinosa varies in colour from light green to green, light yellow to yellow, and intense yellow, as stated by respondents (Table 2). Green (39%) fruit rind colour was the most acknowledged, followed by yellow (24%), light yellow (21%), light green (13%), and least-intense yellow (6%). Females mentioned more light green, green, light yellow, and yellow fruit rinds than men. However, the opposite scenario was observed for intense yellow fruit rind, with males mentioning the more intense yellow fruit rind.
Light green fruit rind was only known to the older women and men in the community. Green fruit rind was most recognised by the young and middle-aged (39%) among females. Elderly men (38%) mentioned more green fruits than women. Women across all age groups (33%) and elderly men (56%) were most accustomed to the light-yellow fruit rind in each gender. Yellow fruits were mostly identified by middle-aged females (48%) and young females (53%) when compared to other age groups in each gender. Intense yellow fruit rind was only known by young and middle-aged males and females (50%).
(b)
Size
S. spinosa was observed to have three distinct sizes in diameter: small (12 cm), medium (14 cm), and large (16 cm). According to the participants, large (46%) fruits were the most mentioned, followed by small (31%) and finally medium (22%) size (Table 2). Information on fruit size was obtained mostly from women than men.
Small fruits were only known by the elderly (54%) and middle-aged women (46%), among females. Middle-aged men recognised more small-sized fruits than other men. Medium-sized fruits were most known by middle-aged women (54%) and older men (50%) in each gender. Large-sized fruit was more popular among middle-aged and elderly women (44%) and men (41%) in each gender.
(c)
Rind texture
Respondents stated that the rind texture of S. spinosa ranged from smooth to rough (Table 2). Smooth (70%) fruits were the most mentioned than rough (30%) fruits. Information on rind texture was mostly obtained by females rather than males. Middle-aged and older men and women were more familiar with the smooth (44%) and rough (46%) rind textures when compared to other age groups in each gender.
(d)
Fruit pulp colour
Respondents claim that the fruit pulp of S. spinosa can vary from white, yellow, light brown, or brown (Table 2). The fruit pulp colours reported were brown (54%), light brown (24%), yellow (14%), and white (8%), respectively. Middle-aged females (50%) were more likely to see white fruit pulp than middle-aged males (20%), elderly females, and the youth (10%). Both middle-aged men and women mentioned the white pulp colour the most in each gender. Yellow fruit pulp was most familiar among the elderly females (40%) and young men. Light brown fruit pulp was most commonly noticed by old men (50%) and women (42%). Brown fruit pulp was mostly perceived by middle-aged women (52%) and men (43%). The youth, middle-aged and older men, on the other hand, were the least aware.
(e)
Fruit pulp texture
S. spinosa fruit pulp texture varies from thick to watery, as described by respondents (Table 2). Most participants usually mentioned thick (67%) textured pulp as opposed to watery (33%). More women were aware of the fruit pulp texture than men among the respondents. Older women (53%) were more conscious of watery fruit pulp textured fruits among females. Middle-aged men were more knowledgeable about watery fruit pulp textured fruits among men. Thick fruit pulp was mostly noticed by middle-aged and elderly men and females.
(f)
Fruit taste
Respondents described S. spinosa fruit taste as varying from very sweet, sweet, and sour (Table 2). According to mentions by respondents, sweet (58%), sour (31%), and very sweet (10%) fruits were found growing in the community. Females were more aware of the fruit taste than males. The very sweet fruits were most known by older women (55%) and middle-aged (50%) men among each gender. Sweet fruits were well known by old women (46%), middle-aged women (43%), and middle-aged and elderly (37%) men, respectively. Sour-tasting S. spinosa fruits are mostly known by middle-aged and elderly women (47%) and men (31%), then compared to the youth.

4. Discussion

4.1. Socio-Demographic Information

Ethnobotanical knowledge of S. spinosa (umHlala) varied according to the age and gender of the participants in the Oyemeni area, KwaZulu-Natal (Figure 2). However, there were more females than males among the people examined for their knowledge of the uses and morphological variation of S. spinosa morphotypes. A similar trend was seen throughout the other age groups, with more females than men interviewed in each category. This high presence of females might be attributed to the majority of examined homesteads that were headed by women, as men in other homesteads were employed away in urban areas. Most South African households are shifting from male to female-headed households [27]. Furthermore, females are often identified as the most respondents in such research because they are seen as the keepers of traditional knowledge [28]. The youth had the least number of interviewed males and females compared with middle-aged and elderly interviewees. This implies that the potentially valuable knowledge and utilisation of this plant is disproportionally resident in the older than younger generation [29]. The findings of this study (Figure 2) agree with the age, gender and dynamics hypothesis, which suggests that various individual socio-cultural and demographic traits such as age and gender are associated with an individual’s level of plant knowledge [30]. There seems to be an erosion of processing knowledge passed on orally from the older to the younger generation because of the adoption of a modern lifestyle in the Oyemeni area. If this indigenous knowledge is not conserved through encouraging, engaging, and educating the youth, information regarding the usage of S. spinosa will eventually be lost.

4.2. The Significance of the isiZulu Name “umHlala” in the Context of Strychnos spinosa

Given the Zulu ethnicity of the residents of Oyemeni, the direct translation of the isiZulu word umHlala, which means “to stay”, was known by everyone in the Oyemeni community. In Zimbabwe, the vernacular name for both S. spinosa and Strychnos cocculoides is “Matamba” because their phenotypic and sensory characteristics are similar [28]. In southern Africa, plants are often well-known by their individual names, significance, use, and/or distinct characteristics [31]. Folk nomenclature remains linked to the socio-cultural, spiritual, and economic lives of the related indigenous groups and folk names of plants are the root of traditional plant biodiversity knowledge [32]. Unlike scientific names, folk names are not sanctioned but are simply preserved through oral tradition [33]. These plant folk names are at the intersection of botany, ethnology, mythology, folklore, linguistics, and philology [34]. However, in scientific terms for S. spinosa the generic name “Strychnos” is derived from the Greek word “strukhnos”, which refers to the properties present in poisonous nightshade [25]. The specific name “spinosa” refers to the spines, which is a morphological characteristic found on some nodes [26].
Unfortunately, only a small percentage of the population knew the significance of the term “umHlala”, which is associated with the use of homestead protection. This might be tied to knowledge loss, as most people lose their culture because of modernisation [35]. Subsequently, ancestral cultural values are abandoned in favour of current ones, resulting in ineffective information translation and not being transferred to future generations [20]. Urgent efforts are required to reverse this trend and capture the existing knowledge of the species to ensure their effective transmission to future generations [30].

4.3. Indigenous Uses of Strychnos spinosa

S. spinosa is mostly utilised for food in the Oyemeni area (Table 1). Only three of the 12 known applications were medicinal, while the other three were for other purposes. Existing investigations have discovered that the species has a high food value [1,10]. In rural regions, various parts of S. spinosa are associated with a range of ethnobotanical uses [16]. The number of people stating a species’ application substantially influences the use-value approach, and a plant may be highly ranked even if only a small number of people claim its various purposes [36]. In the Oyemeni area, S. spinosa is abundant and may be seen growing in almost every homestead. All of these S. spinosa uses match the “ecological apparency theory”, which claims that dominant, large, and plentiful plant species have the highest use values [30].
S. spinosa is well-known and exploited throughout southern and eastern Africa, where its numerous organs are valorised and marketed in various forms in the rural community, especially in Zimbabwe [1,10]. S. spinosa has been processed at a household, small-scale rural level in Zimbabwe for decades, although it has only recently been documented [10]. This was also observed in Oyemeni, where S. spinosa is currently being used for a variety of purposes. The versatility hypothesis has also been developed to propose that adaptability is a favoured selection criterion for broad plant usage [37]. According to this argument, individuals are more likely to keep knowledge, uses, and access to a plant that has a wider range of human use [30]. Currently, members of the genus Strychnos including S. spinosa are receiving more attention as potential new fruit crops due to their high nutritional content and multi-purpose properties in ethnomedicine [5,38]. Strychnos is a genus in the Loganiaceae family with over 200 species, the majority of which are well known for their medicinal and food value [25]. The plant use-value theory states that a plant’s utility in each culture for medicine, food, construction, or trade is directly tied to its botanical family [30].

4.4. Strychnos Spinosa Fermented Food and Drinks

(a)
Fermented maize meal (umBhantshi)
The indigenous methods for processing products of wild fruit species such as Adonsonia digitata, Sclerocarya birrea, Vitellaria paradoxa, Tamarindus indica and Ziziphus mauritiana have been documented earlier [39]. Preparation methods of indigenous food vary in different cultures [8]. In the Oyemeni area, umBhantshi, a fermented combination of maize meal and S. spinosa pulp (Table 1), is similar to mutandabota, a combination of maize meal porridge, and umcaba, a sorghum-based porridge that is mixed with S. spinosa pulp in Zimbabwe [40]. However, there is a wide variation in their preparation. UmBhantshi is prepared by mixing the fruit pulp with either cooked maize meal or crushed maize powder and allowed to ferment overnight before consumption. In Zimbabwe, mutandabota (maize-based porridge) is prepared by boiling the pulp, adding maize meal, and then allowing it to cook until the uniform slurry is obtained [40]. Supplementing S. spinosa fruit with cereal-based staple meals can increase the content of nutrients such as Fe and Zn and reduce starch hydrolysis significantly in vitro, especially for the rural community, as maize meal is a staple food for Sub-Saharan Africa [10,41]. This makes it an important food source for marginalised rural people.
(b)
Fermented porridge (amaHewu)
S. spinosa fermented porridge (amaHewu) is described as a combination of fruit juice and porridge in the Oyemeni area (Table 1). A sieve is used to separate the juice from the pulp of S. spinosa fruit. After separation, the fruit juice is then poured into the newly cooked and still warm maize meal porridge. The mixture is then allowed to cool before being served after fermenting for 24 h. Similarly, in Zimbabwe, S. spinosa pulp is also used to make fermented porridge, but two methods are used in the preparation of the fermented beverage [40]. In the first processing method, the pulp is mashed with a cool stiff maize meal porridge called sadza and combined with the fruit pulp. However, in the second processing method, sorghum or millet flour is added to the fruit pulp without the stiff maize porridge. For both variants, the resultant mixture is incubated for 12–24 h to facilitate fermentation at ambient temperatures, and both are referred to as mahewu [40].
Fermented foods contribute significantly to human diets in Southern Africa because fermentation is a low-cost food preservation strategy that boosts nutritional value and sensory characteristics [42]. Fermentation is the gradual degradation of organic compounds caused by microbes or enzymes that mostly convert carbohydrates to alcohols or organic acids [43]. It makes food safe by not only limiting the growth of dangerous micro-organisms, owing to the lactic acid’s antibacterial action, but also detoxifying aflatoxin. Therefore, fermentation has been considered an effective way to reduce the risk of mineral deficiency among disadvantaged populations [44].
(c)
Alcohol
The preparation of S. spinosa alcohol in the Oyemeni area, South Africa (Table 1), is similar to the preparation in Zimbabwe [40], with a few exceptions. At Oyemeni, S. spinosa alcohol is prepared by mixing the strained fruit juice with little water and yeast and then allowed to ferment for a few days until it is suitable for consumption. Similarly, in Zimbabwe, S. spinosa pulp is combined with either maize or sorghum and yeast is also added. It is then put near the cooking fire and left to ferment naturally for three to four days. When they sell this alcohol, they can make revenue for their families [40].

4.5. Fresh Fruit

Direct consumption of the fruits was also mentioned by community members of the Oyemeni area as they wait for fruits to drop on the ground as an indication of ripening and then pick them up for direct consumption (Table 1). Fruit selection is mostly based on fruit skin colour, fruit size, the size of the place where the peduncle was connected, pleasant scent, and liquefaction. This concurs with the findings in Zimbabwe as fruit harvest occurs by picking the fallen fruits on the ground, and fruit selection is also based on the colour, liquefaction, and taste of fruits [24]. Respondents also selected trees with the best tasting fruits based on previous experience. Community members know where the trees that provide the most delectable fruits are located. Therefore, the traditional gathering of indigenous fruits in southern Africa is heavily reliant on community knowledge and observations [45].
S. spinosa fruits were also popular among the community. The knowledge on the direct consumption of S. spinosa fruits was sourced from more females than males. Older ladies were more informed than younger females. The youth was better knowledgeable than older men among the males. Gathering and fruit selection are mainly activities conducted by women during their daily chores when they tend the field or collect firewood and by children going to and from the school or as they herd cattle [28]. Some women in Oyemeni also sell these fruits at informal stands in town to gain income for their families. In KwaZulu-Natal, commercialisation of indigenous plants is well developed in the informal sector, with a large and active trade. An extensive network exists, which harvests large volumes of plants from wild populations and sells them to consumers, who may be both rural and/or urban [9]. S. spinosa grows in parts of South Africa such as the Eastern Cape, KwaZulu-Natal, Limpopo, and Mpumalanga, where it is directly consumed by the rural communities in those areas [5]. Many studies have shown that the consumption of this fruit has several advantages because it is a source of energy and nutrients [17,46]. Previous studies in other countries such as Benin [1], Ethiopia [47], Malawi [48], and Zimbabwe [40] also mention the direct consumption of S. spinosa fruits.

4.6. Juice

Aside from eating the fruit directly, respondents described S. spinosa fruit juice as a blend of the fruit’s contents and water (Table 1). The rind of the fruit is broken apart, and the pulp and seeds are poured into a container filled with cold water. Depending on the sweetness of the fruit, sugar may be added. The mixture can be consumed shortly after it has been combined. This preparation method is similar to the one used in Zimbabwe, where the whole fruit pulp may be used to prepare juice [40]. Pulp is sieved or strained with a mesh sieve substituted traditionally with a woven high-density polyethylene sack. Water and lemon fruit juice or citric acid is added, depending on availability as a preservative for the juice. The juice is boiled, and sugar is added, also depending on the consumer’s preference [40]. The use of indigenous fruits for making juice and beverage has been used for many years. Rural households in Zambia also process indigenous fruits, such as Anisophyllea boehmii, Parinari curatellifolia, and Uapaca kirkiana, into fruit juices [49].

4.7. Jam

S. spinosa fruits are also often enjoyed in other forms such as jam and spread on steam bread or wheat bread in the Oyemeni area (Table 1). Respondents described S. spinosa jam as a thick fruit spread made with de-seeded fruit pulp pieces. However, in their jam preparation, they do not add pectin, as the fruit’s pectin depolymerisation allows jams to set and spread well [10]. However, the preparation method in Zimbabwe differs slightly as the pulp is sieved to separate it from the seeds, sugar is added, and then cooked for 20 min to a thick texture [40]. S. spinosa jam was described mainly by males than females. The reason is that the jam acquired favour among the young men while on duty during livestock care. This agrees with previous studies that reported young men gathering fruits while tending livestock, and women collected them while collecting wood in Zimbabwe [40]. The commercial potential of S. spinosa fruit to produce jam has been proposed recently [50]. Already other fruit trees such as Berchemia zeyheri, Bridelia micrantha, Dovyalis caffra, Englerophytum magalismontanum, Ficus sur, Haperphyllum caffrum, Sclerocarya birrea, and Rhoicissus temontosa are being utilised in jam preparation in southern African rural households [13].

4.8. Homestead Protection and Livestock Increase

Homestead protection, according to responders, is a traditional ritual belief that is aimed at securing and protecting the home against witchcraft, sorcery, or any evil spirits (Table 1). Four unripe S. spinosa fruits are placed in strategic places around the homestead. Similarly, some hunters in Benin believe the species protects them from brutal animal attacks, claiming that just racing backwards towards a standing S. spinosa tree and clinging to it can save them from being recognised and attacked by dangerous animals [1]. The use of plant rituals might be tied to religious or secular activity [51]. Furthermore, other people in Benin crack open ripe fruits, and the pulp is sucked while pronouncing incarcerations once a year, and it is believed that this act will protect one from firearms by acting as bulletproof [1].
S. spinosa fruits that have developed in a rare cluster form are harvested off a tree with the peduncle still intact. The cluster is then buried in the centre of the kraal, and it is believed that the livestock which occupies that kraal will be able to give birth to twins during the breeding season. The Doctrine of Signature suggests that a plant’s form recapitulates its use, and every plant having useful medicinal properties bears somewhere about it the likeness of the organ or of the part of the body upon which it exerts a healing action [30]. S. spinosa fruits that form in a cluster are analogous to amniotic sacs with twins, and the peduncle represents the umbilical cord in this morphological concept. Similarly, in Benin, it is believed that the presence of an individual of the species in the field attracts blessings from the gods of the earth for increased crop yields, especially yams [1].
Most African cultures have diverse beliefs about indigenous fruits, which has influenced how these plant species are used [52]. Many ethnic groups throughout the world practice their ritual beliefs and utilise plant variety for ritual purposes. Approaches to plant diversity conservation that are based on cultural and religious values are frequently more sustainable than those that are only focused on legislation or regulation. Traditional beliefs and rituals are the indigenous methods of plant management adopted to sustain indigenous plants exploited by rural communities [53].

4.9. Snakebite

Respondents stated that an immature S. spinosa fruit is opened, and the injured person is then required to lick the bitter fruit (Table 1). Likewise, studies in Nigeria found that the extracts from unripe fruits are used as an antidote against snakebite venom [54]. Every year, up to 2.7 million people are affected by snakebite envenoming, the majority of whom reside in some of the world’s most isolated, underdeveloped, and politically marginalised tropical rural regions where there are poor health services [55]. People in these areas have achieved notable success in treatment for centuries by using medicinal plants to treat the effects of snake envenomation [56]. The mechanism by which medicinal plants neutralize the toxic venom constituents is still unknown, but many hypotheses have been proposed, such as protein precipitation, enzyme inactivation, proteolytic degradation, metal chelation, antioxidant action, and a combination of these mechanisms [57].

4.10. Firewood

Respondents stated that due to its dry nature, S. spinosa wood creates an excellent fire (Table 1). Although most wild woody plant species can be used as a source of fuel for indigenous peoples, many species are recognized for particular burning qualities [58]. The species is recognised for its toughness, and therefore S. spinosa wood is utilized in carving and carpentry, as well as for firewood and char [1]. S. spinosa is among other species which are used for firewood in Limpopo, such as Dichrostachys cinerea, Grewia flavescens, Pappea capensis, and Sclerocarya birrea [53]. Some fuelwood species provide multi-purpose benefits in a variety of ways, including fodder, medicinal, food, and cultural purposes [58]. S. spinosa exhibits this multi-purpose trait as well, with applications also ranging from food to medical to cultural.

4.11. Food Allergy and Stomachache

Respondents indicated that when a new seasonal meal is introduced, some people tend to respond badly by falling ill after eating it (Table 1). In order to prevent such a response, it is necessary to boil tiny bits of S. spinosa bark and drink the concussion. The causes of the food allergy epidemic are unknown, although various explanations have been proposed, including the hygiene theory, the general allergy march, and epigenetics [59]. Traditional herbal medicine is among the treatments that have the potential to regulate allergic reactions [60]. The efficacy of a medicinal plant against any specific ailment is mostly determined by the presence and quantity of phytochemicals found in the plant [61]. Many phytochemicals found in various parts of S. spinosa remain critical in understanding its future possibilities in medicine. S. spinosa leaves, branches, seeds, and fruit pericarp were shown to contain a variety of phytochemicals [5]. S. spinosa is an indigenous fruit exhibiting various health-promoting benefits against a variety of pathogens due to its diverse nutritional and phytochemical constituents [12]. At Oyemeni, respondents said that small bits of the bark are boiled with water, and the decoction is then sipped to relieve stomachache. In traditional medicine, S. spinosa is often used in the treatment of stomach-related aches [1].

4.12. Morphological Variation of Strychnos spinosa

(a)
Leaf traits
The colour of S. spinosa leaves, which were obtained from respondents, ranged from green to dark green (Table 2). Similarly, in Nigeria, leaf colour also ranged from light to dark green above and paler beneath. The leaves turn yellow in the dry season before they fall off [26]. Leaf traits determine many aspects of plant function, including rates of photosynthesis and transpiration, investment costs for leaf construction, plant nutrient requirements and resilience to temperature extremes [62]. Trait values vary within and among species and along environmental gradients [63].
At Oyemeni, the form of S. spinosa leaves varied between rounded and elongated, as described by respondents (Table 2). However, in Nigeria, the leaf shape was observed to be more rounded [26]. Strychnos spinosa shows a great deal of phenotypic variation in leaf size and form [9]. Since the origins of botany, leaf characteristics, especially those concerning form, have been extensively used in conventional text-based taxonomic keys for plant identification [64]. The reason is that, although species’ leaf form differs in detail, general form types can easily be distinguished by people [65]. Plants of the same species may show significant differences in their morphological traits depending on their geographical location and other abiotic variables, growth stage, and season [66].
(b)
Fruit traits
The rind of S. spinosa fruits varied in colour from light green to green, light yellow to yellow, and intense yellow, as stated by respondents (Table 2). On the contrary, in Zimbabwe, the fruit rind is often shiny green and some with yellow spots when young, but they turn yellow or brown when mature [9,26]. Respondents observed three distinct fruit sizes (in diameters): small (12 cm), medium (14 cm), and big (16 cm). However, according to Mwamba [9], the fruits range in size from 7 to 15 cm in diameter. Respondents also mentioned that there was a relationship between fruit size and taste, where smaller fruits were sweeter than bigger ones.
Respondents stated that the rind texture of S. spinosa ranged between smooth and rough (Table 2). They also mentioned that it is usually the rough-textured fruits which are sweeter in taste than the smooth-textured ones. Studies on S. spinosa have reported only on a smooth textured rind [5,9,16,67,68]. However, the fruit of S. cocculoides may have a granular rind, providing it with a rough texture [9].

4.13. Organoleptic Variation of Strychnos spinosa

Urgent work is needed on assessing the organoleptic properties, such as taste, texture, consistency, and palatability of Strychnos products [9]. Wide variations exist in the general description of taste, colour, texture, and flavour within the species [67]. Based on prior experience, at Oyemeni, community members can choose trees with the best-tasting fruits, and they can also associate morphological and organoleptic traits of the species. In Zimbabwe, community members use external visual attributes such as colour, size, and surface structure to predict the taste of the fruit [40].
S. spinosa fruit pulp texture varied from being thick to watery, as described by respondents. Liquefaction is a common maturity indicator, but community members at Oyemeni are also able to detect the fruit texture by shaking the ripe fruit close to the ear and listening for the sound of sloshing pulp. The sloshing pulp’s watery sound indicates a watery texture, whereas a thick texture makes less noise when shaken. This is similar to fruits in Zimbabwe, where the pulp texture is characterized as a thick gel or juicy [67]. The natural plant enzymes polygalacturonase (PG), pectinmethylesterase (PME), lyase, and rhamnogalacturonase partially solubilize pectin and cellulose during ripening, contributing to changes in texture and juiciness of fruits [10].
Respondents claimed that the fruit pulp of S. spinosa can vary from white, yellow, light brown, or brown (Table 2). Similarly, in Nigeria, the pulp was observed to be light brown, and in Zimbabwe, pulp colour ranged from orange to brown [10,26]. S. spinosa fruit tasted very sweet, sweet, and sour, according to respondents. This is consistent with the reports in Benin, which state that the fruit pulp is somehow acidic and sweet [1]. The acidic elements that mix with sugars to produce the species’ uniquely blended acid-sweet flavour are attributed to the presence of organic acids such as citric, malic, and succinic acids [9,10]. The sugar content of fruit has a strong influence on its sweetness. It has been claimed that the taste of S. spinosa is influenced by the degree of ripeness as determined by the sugar profile [67]. The concentrations of soluble sugars, organic acids and fructose have a significant impact on fruit taste as well as the stickiness of the pulp [40].
For many years, people have associated basic tastes with specific colours. Green colour often correlates with bitter foods, yellow fruits sour taste, and orange with a sweeter taste [69]. This was evident at Oyemeni, where the respondents mentioned that white fruits were not very sweet, light yellow and yellow fruits were sweet and sour, and the brown pulp was the sweetest. Currently, there are no reports on the range in pulp colour in relation to taste within S. spinosa. The plant use value hypothesis suggests that the utilitarian value local people associate with a provided plant species is solely a function of the traits of the plant species [30].
The findings of this study on the utilization of S. spinosa have the potential to address sustainable food security issues. The indigenous knowledge of the use of S. spinosa can significantly contribute to the Sustainable Development Goals, such as contributing to household income as fruits are sold in local markets to generate revenue, alleviating hunger and providing sustainable nutritional needs for rural communities in particular, and mitigating the impact of climate change as S. spinosa is drought tolerant [40,45].

5. Conclusions

S. spinosa plays an important role in local food security and health care in rural communities. Processing S. spinosa and using it for product diversification is still limited in more affluent urban areas due to the lack of indigenous knowledge, and awareness of its potential is still lacking. From an innovation perspective, some of the identified local food recipes are potential candidates that can be developed as nutrient-dense health food products. S. spinosa fruit and its by-products can contribute to the economy and rural livelihood in Africa. Especially faced with the current crisis of food insecurity, there is a need to develop more innovative survival strategies. However, this still requires further investigation into intra-specific variation in the species germplasm. Collected germplasm should then be used to obtain information on variation within the species so that materials used for selection would be genetically based. This study also pointed out the existing knowledge gaps within the species concerning rough skin texture and its correlation with pulp taste, as well as pulp colour range and its correlation with pulp taste, which were recorded for the first time, and require further laboratory-based scientific investigation. The similar phenotypic and sensory characteristics of S. spinosa and S. cocculoides as the species also require investigation of possible hybridization. The findings of the study were limited by sourcing the baseline information on the uses and morphological diversity among S. spinosa morphotypes from a narrow geographical area, the Oyemeni area, northern KwaZulu-Natal. For future purposes, comprehensive knowledge can be sourced from other areas where S. spinosa grows in KwaZulu-Natal and the whole country.

Author Contributions

Conceptualization, Z.M., N.RN., G.E.Z. and C.Z.; methodology, Z.M. and N.R.N.; software, Z.M.; validation, N.R.N., G.E.Z. and C.Z.; formal analysis, Z.M.; investigation, Z.M.; resources, Z.M.; data curation, Z.M.; writing—original draft preparation, Z.M.; writing—review and editing, N.R.N.; supervision, N.R.N., G.E.Z. and C.Z.; project administration, Z.M.; funding acquisition, N.R.N. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Ethics Committee of UNIVERSITY OF ZULULAND (protocol code: UZREC 171110-30 Dept. 2016/120 and date of approval: 7 September 2016).

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

Not applicable.

Acknowledgments

Authors would like to thank the community of Oyemeni area for generously sharing their valuable information on S. spinosa.

Conflicts of Interest

The authors declare no conflict of interest.

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Sustainability 14 06623 g001 550
Figure 1. Strychnos spinosa leaves (A), fruits (B), Flowers (C), and tree with mature fruits (D).
Figure 1. Strychnos spinosa leaves (A), fruits (B), Flowers (C), and tree with mature fruits (D).
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Figure 2. Gender and age of interviewees (n = 100).
Figure 2. Gender and age of interviewees (n = 100).
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Table
Table 1. Uses of Strychnos spinosa by Oyemeni community, KwaZulu-Natal.
Table 1. Uses of Strychnos spinosa by Oyemeni community, KwaZulu-Natal.
CategoryUseRespondentsGenderAge (Years)
F [N (%)]18–34 N(TFI; SFI)35–54 N(TFI; SFI)≥55 N(TFI; SFI)
FoodFermented maize meal (umBhantshi)97F [66 (68)]13 (13; 20)26 (27; 39)27 (28; 41)
M [31 (32)]12 (13; 39)9 (9; 29)10 (10; 32)
Fruit85F [61 (72)]26 (31; 43)5 (6; 8)30 (35; 49)
M [24 (28)]10 (12; 42)6 (7; 25)8 (9; 33)
Juice23F [17 (74)]7 (30; 41)4 (17; 24)6 (26; 35)
M [6 (26)]2 (9; 33)1 (4; 17)3 (13; 50)
Jam16F [4 (25)]4 (25; 100)0 (0; 0)0 (0; 0)
M [12 (75)]6 (38; 50)2 (13; 17)4 (25; 33)
Alcohol7F [5 (71)]0 (0; 0)0 (0; 0)5 (71; 100)
M [2 (29)]0 (0; 0)2 (29; 100)0 (0; 0)
Fermented porridge (amaHewu)6F [5 (83)]1 (17; 20)2 (33; 40)2 (33; 40)
M [1 (17)]0 (0; 0)0 (0; 0)1 (17; 100)
OtherHomestead protection41F [29 (71)]3 (7; 10)7 (17; 24)19 (46; 66)
M [ 12 (29)]0 (0; 0)7 (17; 58)5 (12; 42)
Snakebite24F [15 (63)]3 (13; 20)4 (17; 27)8 (3; 53)
M [ 9 (38)]0 (0; 0)5 (21; 56)4 (17; 44)
Fire10F [9 (90)]4 (40; 44)1 (10; 11)4 (40; 44)
M [1 (10)]0 (0; 0)0 (0; 0)1 (10; 100)
Food allergy10F [ 9 (90)]3 (30; 33)3 (30; 33)3 (30; 33)
M [1 (10)]0 (0; 0)1 (10; 100)0 (0; 0)
Increasing livestock7F [7 (100)]0 (0; 0)5 (71; 71)2 (29; 29)
M [0 (0)]0 (0; 0)0 (0; 0)0 (0; 0)
Stomachache7F [5 (71)]0 (0; 0)0 (0; 0)5 (71; 100)
M [2 (29)]0 (0; 0)2 (29; 100)0 (0; 0)
F, female; M, male N, number; (FI), frequency index expressed as percentage; TFI, total frequency index; SFI, specific frequency index.
Table
Table 2. Morphological and organoleptic variation of Strychnos spinosa at Oyemeni, KwaZulu-Natal.
Table 2. Morphological and organoleptic variation of Strychnos spinosa at Oyemeni, KwaZulu-Natal.
Leaf Trait Total Mention per CategoryGenderAge (Years)
FIF [N (%)]18–34 N (TFI; SFI)35–54 N (TFI; SFI)≥55 N (TFI; SFI)
ColourGreen78F [68 (70)]7 (7; 10)30 (31; 44)31 (32; 46)
M [29 (30)]7 (7; 24)11 (11; 38)11 (11; 38)
Dark green22F [20 (74)]4 (15; 20)10 (37; 50)6 (22; 30)
M [7 (26)]3 (11; 43)2 (7; 29)2 (7; 29)
ShapeRounded74F [62 (74)]5 (6; 8)26 (31; 42)31 (37; 50)
M [22 (26)]4 (5; 18)8 (10; 36)10 (12; 45)
Elongated26F [18 (62)]3 (10; 17)7 (24; 39)8 (28; 44)
M [11 (38)]4 (14; 36)3 (10; 27)4 (14; 36)
Fruit trait
Rind colourLight green13F [19 (76)]0 (0; 0)0 (0; 0)19 (76; 100)
M [6 (24)]0 (0; 0)0 (0; 0)6 (24; 100)
Green39F [57 (78)]22 (30; 39)22 (30; 39)13 (18; 23)
M [16 (22)]5 (7; 31)5 (7; 31)6 (8; 38)
Light yellow21F [30 (77)]10 (26; 33)10 (26; 33)10 (26; 33)
M [9 (23)]2 (5; 22)2 (5; 22)5 (13; 56)
Yellow24F [31 (67)]14 (30; 45)15 (33; 48)2 (4; 6)
M [15 (33)]8 (17; 53)7 (15; 47)0 (0; 0)
Intense yellow3F [2 (33)]1 (17; 50)1 (17; 50)0 (0; 0)
M [4 (67)]2 (33; 50)2 (33; 50)0 (0; 0)
SizeSmall31F [48 (77)]0 (0; 0)22 (35; 46)26 (42; 54)
M [14 (23)]1 (2; 7)7 (11; 50)6 (10; 43)
Medium22F [28 (64)]2 (5; 7)15 (34; 54)11 (25; 39)
M [16 (36)]2 (5; 13)6 (14; 38)8 (18; 50)
Large46F [64 (70)]8 (9; 13)28 (31; 44)28 (31; 44)
M [27 (30)]5 (5; 19)11 (12; 41)11 (12; 41)
Rind textureSmooth73F [70 (80)]8 (10; 11)31 (40; 44)31 (40; 44)
M [28 (20)]7 (9; 25)11 (14; 39)10 (13; 36)
Rough30F [24 (65)]2 (5; 8)11 (30; 46)11 (30; 46)
M [13 (35)]3 (8; 23)4 (11; 31)6 (16; 46)
Pulp colourWhite8F [7 (70)]1 (10; 14)5 (50; 71)1 (10; 14)
M [3 (30)]1 (10; 33)2 (20; 67)0 (0; 0)
Yellow14F [10 (59)]3 (18; 30)3 (18; 30)4 (24; 40)
M [7 (41)]3 (18; 43)2 (12; 29)2 (12; 29)
Light brown24F [24 (80)]6 (20; 25)8 (27; 33)10 (33; 42)
M [6 (20)]2 (10; 33)1 (3; 17)3 (10; 50)
Brown54F [46 (69)]1 (1; 2)24 (36; 52)21 (31; 46)
M [21 (31)]4 (6; 19)9 (13; 43)8 (12; 38)
Organoleptic Trait
Pulp textureWatery33F [30 (70)]5 (15; 17)9 (27; 30)16 (48; 53)
M [13 (30)]3 (9; 23)6 (18; 46)4 (12; 31)
Thick67F [63 (72)]6 (7; 10)30 (34; 48)27 (31; 43)
M [24 (28)]6 (7; 25)8 (9; 33)10 (11; 42)
TasteVery sweet10F [11 (65)]1 (6; 9)4 (24; 36)6 (35; 55)
M [6 (35)]1 (6; 17)3 (2; 50)2 (12; 33)
Sweet58F [67 (69)]7 (7; 10)29 (30; 43)31 (32; 46)
M [30 (31)]8 (8; 27)11 (11; 37)11 (11; 37)
Sour31F [36 (69)]2 (4; 6)17 (33; 47)17 (33; 47)
M [16 (31)]6 (12; 38)5 (10; 31)5 (10; 31)
F, female; M, male; N, number; (FI), frequency index expressed as percentage; TFI, total frequency index; SFI, specific frequency index.
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Mbhele, Z.; Zharare, G.E.; Zimudzi, C.; Ntuli, N.R. Indigenous Knowledge on the Uses and Morphological Variation among Strychnos spinosa Lam. at Oyemeni Area, KwaZulu-Natal, South Africa. Sustainability 2022, 14, 6623. https://doi.org/10.3390/su14116623

AMA Style

Mbhele Z, Zharare GE, Zimudzi C, Ntuli NR. Indigenous Knowledge on the Uses and Morphological Variation among Strychnos spinosa Lam. at Oyemeni Area, KwaZulu-Natal, South Africa. Sustainability. 2022; 14(11):6623. https://doi.org/10.3390/su14116623

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Mbhele, Zoliswa, Godfrey Elijah Zharare, Clement Zimudzi, and Nontuthuko Rosemary Ntuli. 2022. "Indigenous Knowledge on the Uses and Morphological Variation among Strychnos spinosa Lam. at Oyemeni Area, KwaZulu-Natal, South Africa" Sustainability 14, no. 11: 6623. https://doi.org/10.3390/su14116623

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