1.NounA green vegetable dye from China, obtained from one or more species in the genus Rhamnus- probably Rhamnus globosa (syn. Rhamnus chlorophora), but Rhamnus utilis, as well as a mixture of Rhamnus davurica (or "Rhamnus dahurica") and Rhamnus globosa (as Rhamnus tinctoria) have also been given as the true source.