SOME USEFUL PLANTS AND PLANT PRODUCTS 327 



have very largely displaced vegetable dyes. However, some 

 .dyestuffs obtained from plants are still important commer- 

 cially. 



Indigo is one of the vegetable dyes that has been largely 

 replaced, though it is still used to some extent as for 

 example in " bluing . " 1 1 is obtained from the j uices of several 

 tropical plants, mostly species of Indigofera. Logwood 

 extract is a red substance derived from the wood of -a tree 

 growing in Central America and the West Indies. It can be 

 used only in connection with a mordant, which causes the 

 fabric or other substance that is to be dyed to take and hold 

 the color. The color obtained is usually black, but it may 

 be violet, blue, or gray, depending upon the mordant used. 

 Madder is a red dye produced by powdering the dried roots 

 of a plant grown in central Europe and southern Asia. 

 Arnotto, a yellow dye used in coloring butter and cheese, is 

 made from the pulp of the fruit of a shrub of Central and 

 South America and the West Indies. Safflower, a red color- 

 ing matter used as a flavoring, in face rouge, and in making a 

 dye for silk, is the dried flowers of a plant of the composite 

 family. Other vegetable dyes are fustic, quercitron, saffron, 

 henna, litmus, and turmeric. 



