Indigenous knowledge on the uses and factors that determine the use of strychnos spinosa lam found in Bushbuckridge, Mpumalanga, South Africa.

Abstract

In sub-Saharan Africa, Indigenous knowledge (IK) is a vital source of information about the local environment, including the identification and use of various plant species. One of the plant species that has attracted much attention in the area is Strychnos spinosa Lam. (S. spinosa), commonly known in English as ‘spiny monkey orange’ or ‘umKwakwa’ in isiZulu and isiXhosa, and used by local communities for medicinal, nutritional, and cultural purposes. The aim of this study was to document the ethnobotanical uses of Strychnos spinosa among selected communities in Bushbuckridge, Mpumalanga Province, South Africa, and to identify the taxonomic identity of market-sold Strychnos products using DNA barcoding. This study investigates the ethnobotanical uses and taxonomic authenticity of S. spinosa in Bushbuckridge, Mpumalanga Province, South Africa. An ethnobotanical survey was conducted through in-depth interviews with 108 participants selected using purposive and snowball sampling techniques across six settlements in Bushbuckridge Local Municipality, Mpumalanga Province, South Africa. The sites were selected based on their high reliance on indigenous plant resources and the presence of active informal medicinal plant markets, while participants were selected for their knowledge and experience in use of S. spinosa. Through qualitative and quantitative analyses, the research revealed the diverse uses of the plant, including its nutritional, medicinal and cultural significance. The plant’s average Use Value (UV) and Relative Frequency of Citation (RFC) were determined and found to be 1.9 and 0.4, respectively. The findings revealed that 93% of participants depended on wild harvesting, while concerns about its declining availability due to urbanisation, agriculture and climate change were commonly reported. Market participation was high, with 99% of respondents selling S. spinosa products. However, conservation efforts were deemed inadequate, with 46% of participants pointing out lack of formal protective measures. DNA barcoding was used to verify the authenticity of fruit, seed and powdered samples of Strychnos spp. sourced from Bushbuckridge Local Municipality, Mpumalanga Province, South Africa. DNA extraction and amplification were performed using two plastid markers, rbcLa and matK, followed by Sanger sequencing. Sequences obtained were aligned and analysed using BLAST against GenBank. DNA barcoding results revealed that none of the analysed market samples matched S. spinosa. Instead, samples showed a high degree of sequence identity (≥99% similarity) with other Strychnos species, v particularly S. madagascariensis, S. innocua, and S. xanthoclada. Results confirm species identity through DNA barcoding analysis and suggest possible misidentification or substitution within local markets, despite the ethnobotanical focus on S. spinosa. The results confirm that molecular identification is feasible even for degraded and processed material. The phylogenetic placement of all Bushbuckridge Local Municipality samples within a well-supported S. madagascariensis clade further validated BLAST identifications and showed no evidence of adulteration or substitution. Collectively, the study underscores the importance of integrating Indigenous Knowledge with molecular techniques to enhance the safety of medicinal plants, conserve biodiversity, and inform evidence-based policies and regulations aligned with the Nagoya Protocol and South African biodiversity frameworks. This work provides novel molecular data on southern African Strychnos, supports pharmacovigilance in traditional medicine markets. This study also provides evidence- based insights into the mismatch between ethnobotanical knowledge and molecular identification, revealing that market-sold products may not correspond to S. spinosa. This highlights potential misidentification or substitution within local medicinal plant markets and underscores the critical role of DNA barcoding in ensuring species authenticity and protecting indigenous knowledge systems.