Leonotis leonurus L. R. Br. (Lamiaceae): Anatomical features and recreational use survey of a possible substitute for Cannabis sativa L. (Cannabaceae)

Abstract

Leonotis leonurus L. R. Br. (Lamiaceae) is a medicinal plant native to the South African continent also employed as a recreational drug and a substitute to Cannabis sativa L. (Cannabaceae). Given the interest of the last mentioned species as a source of treatments for epilepsy among many other pathologies and its possible substitution for L. leonurus, the aim of this article is obtain anatomical and micrographical characters for its identification in chopped or powdered material and to survey the user´s perceptions about this plant based in posts extracted from a recreational drug user Internet forum. L. leonurus leaves have pluricellular tector trichomes and two classes of pluricellular trichomes with unicellular and pluricellular heads, styloid crystals in its mesophyll among many other characters, while the flowers have wooly trichomes and characteristic pollen granules. Regarding the Internet forum survey, it was reported that L. leonurus leaves and flowers were the employed parts and that the mode of use was smoked. The reported effect was sedative. The anatomical data reported in this article may help to identify L. leonurus in pharmaceutical or forensic contexts.