- a coloring matter of certain higher plants that imparts a bluish or reddish color
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby
- A water-soluble pigment in plants. It occurs in solution in the cell sap and is responsible for red, blue, and violet colors.
Source: Curtis, Helena. 1968. Biology. New York, NY. Worth Publishers