Sifting through cycads: A guide to identifying the stem fragments of six South African medicinal Encephalartos species

Sixty-three percent of the world's cycad taxa are threatened with extinction. In South Africa, 25 of the 38 indigenous species are categorised as Threatened on the IUCN Red List, primarily due to illegal collecting. Three of the country's Encephalartos species are already Extinct in the Wild, while 10 Critically Endangered endemic Encephalartos species are undergoing rapid local extirpations across their ranges. Nearly two-thirds of South Africa's Encephalartos species are used for traditional medicine, some of which are sold in traditional medicine markets in the form of bark strips and stem fragments. The leafless Encephalartos stems encountered in the medicinal and horticultural trades are generally difficult to identify to species and, since species identification of South African Encephalartos using DNA barcoding is not yet feasible, alternative methods of identification are required. To determine the identity of the species sold in South Africa's two largest traditional medicine markets in KwaZulu-Natal (KZN) and Gauteng, surveys were conducted in the Warwick and Faraday markets respectively. Stem fragment samples purchased from the vendors in the markets were identified to species using stem and leaf base morphological characters in tandem with harvesting locality records. Six KZN Encephalartos species were successfully identified viz. E. ferox, E. ghellinckii, E. natalensis, E. ngoynaus, E. senticusos and E. villosus. Photographs of stem fragments and leaf bases of each species are presented here with supplementary quantitative and descriptive stem anatomical data. This paper therefore presents an identification guide to assist researchers and law enforcement officers in the identification of Encephalartos species unlawfully harvested for the traditional medicine and horticultural trades. The guide is thus also useful in the emerging discipline of wildlife forensics, and offers a unique approach to determining difficult-to-identify Encephalartos stem material.

► Correct identification of cycads in horticultural and medicinal trades is crucial.
► Cycads in South African medicinal plant trade identified using morphology and origins
► Six Encephalartos species were successfully identified.
► A photographic identification guide to these species is presented.