Coleus scopulideorum (Lamiaceae), a new Critically Endangered monocarpic mint from the Bakossi Mountains, Cameroon — described, despite the loss of critical material

Coleus scopulideorum B.J.Pollard (Lamiaceae), a distinctive synchronous-flowering herb from Nyale Rock, Bakossi Mountains, Cameroon is described and illustrated. Good practice to guide decision-making over discarding herbarium material is proposed following the loss of specimens that were key to the description of this species. Notes on its taxonomic relationships, ecology, ethnobotany, and conservation are presented, with an illustration. A key is provided to the four wild species of Coleus Lour. with yellow or partly yellow flowers known from western Cameroon (SW and NW Regions).