Desert species Tribulus cistoides (Zygophyllaceae), rediscovery in India after 150 years

Tribulus cistoides is rediscovered after 150 years in India from the Sikar district in the Rajasthan State. This study also reported first natural location of this species for flora of India since no one has reported its occurrence in wild in India. The species is closely allied to T. terrestris and T. rajasthanensis but differs in having larger flower with longer style and 2 larger and 2 shorter spines. The authors suggest calculating its IUCN status on the basis of IUCN red list criteria. For this purpose, more field exploration surveys with detailed studies are needed to know its status in India, particularly in arid and semi-arid regions. The genus Tribulus belonging to family Zygophyllaceae is represented in India by 6 species and 3 varieties. The present paper envisages with its taxonomic description, photo plates, distribution map and identification key with their closely allied species for easy identification.