Resumen
The present study deals with the naturalization of wild population of a threatened and critically endangered Himalayan medicinal plant i.e. Saussurea costus (Falc.) Lipsch. The population of S. costus has been recorded at three different places during the scientific expedition (2015). It has always been argued that the individuals found earlier at one place can never be considered as the species has naturalized itself in Nanda Devi National Park and thought to be an escape from cultivation. However, during the scientific expedition 2015, it has been reported from two more places which were very far from their previous location. The naturalized proliferation of the species have provided a base for long term study.