Phytogeographical and Ethnobotanical Attributes of Amaranthus spp. in Malawi

Abstract

The Amaranthus genus, widely distributed across tropical and subtropical regions, is valued for both its nutritional and medicinal properties. This significance led to an investigation into its diversity and traditional applications within Malawi. Between October 2024 and January 2025, a comprehensive study was undertaken, combining phytogeographical mapping and ethnobotanical surveys to assess species distribution and gather insights from local communities about the genus’s uses. The phytogeographical analysis utilized the Botanical Research and Herbarium Management System (BRAHMS) to evaluate spatial distribution patterns. Concurrently, the ethnobotanical component collected qualitative data through field interviews with 600 informants. Statistical indicators such as informant consensus factor (FIC), frequency of citation (Fc), fidelity level (FL), and use value (UV) were applied to quantify the relative importance of various species and their traditional applications. This research identified eight species of Amaranthus in 5 districts across Malawi. Among them, six species— A. hypochondriacus L., A. hybridus L., A. dubius Mart. Ex Thell., A. spinosus L., A. thunbergii Moq., and A. cruentus L . —were consistently cited by informants for their medicinal utility. Notably, A. hyp ochondriacus L. and A. hybridus L. were the most commonly used, with citation frequencies of 13.67% and 10.16%, respectively. A. hyp ochondriacus L. emerged as particularly important, showing a high FIC of 0.97 and the highest FL (86.75%) in relation to its use in managing blood pressure. Its UV was measured at 0.75, and 95.2% of informants reported using it as a decoction to treat ailments affecting the entire household. Furthermore, 88.32% of informants recognized the nutritional value of Amaranthus species. Of these, 65% highlighted their high vitamin content, 30% emphasized their protein richness, and 5% associated them with promoting children’s growth. Overall, the study confirmed the presence of eight Amaranthus species in Malawi. While 23% of the informants used these plants for medicinal purposes, the majority relied on them as a food source. The findings underscore the need for further research into their pharmacological and nutritional properties to enhance understanding and utilization.