Jurinea macrocephala Benth.- the Commercial Source of Dhoop

The rhizomes and ischolar_mains of Jurinea macrocephala Benth., on extraction with organic solvent, yield a caoutchouc like material. It was found that chloroform extract gives the highest percentage of crude caoutchouc which is sticky and resilient in nature. Thus determination of chloroform extractive offers a convenient method for evaluation of dhoop samples. In the present study dhoop samples from iS different geographical area., covering the whole commercial dhoop producing zone, were found to vary in their caoutchouc , contents. The samples of dhoop collected from Tundah, Bagh and Belaj dhars of Chamba valley and Baramulla range of Kashmir valley give the highest caoutchouc content. The assay value obtained by this method have been found to be in close agreement with the commercial grades of dhoop, that is, superior grades give higher caoutchouc content and inferior grades give a low content. Microchemical and chemical evidence is a1so presented for the presence of caoutchouc in the rhizomes.