The giant tree rhododendron (R. protistum var. giganteum) is one of the most famous plants in China, and is critically endangered. As previous conservation efforts only focused on the two recorded populations of this variety, key issues regarding relatedness to R. protistum var. protistum still remain. Our field investigations and SSR analysis of the two varieties in China and Nepal suggest that the two varieties are not significantly different, and we suggest that limited conservation resources could be better used elsewhere given the numerous endangered plants urgently needing protection in China. We suspect that the problems we identified in this study will also apply to many other taxa in developing countries identified as endangered on the basis of incomplete information. (C) 2018 The Authors. Published by Elsevier B.V.