Grazielanthus is a monotypic, dioecious and microendemic plant genus of the Brazilian Atlantic Forest. Its only species, Grazielanthus arkeocarpus, is categorized as Critically Endangered on the IUCN Red List and comprises only one small population, in the Poço das Antas Biological Reserve, Rio de Janeiro State. Collaborative activities have been developed since 2013 to implement in situ and ex situ conservation actions for this species. Successful in situ planting has increased the number of individuals in its natural population. Ex situ conservation efforts have resulted in the cultivation of the species in two Brazilian living plant collections, and this will soon increase to three collections.
