Rocella tinctoria, commonly known as the dye lichen, is a type of lichen that grows on rocks and trees in coastal areas. It is primarily found in tropical and subtropical regions. This lichen is notable for its ability to produce a natural dye called orcein, which has been used for centuries to color textiles and other materials. The dye extracted from Rocella tinctoria has a rich reddish-purple hue and was historically significant in the textile industry, especially in the production of wool and silk fabrics. Today, it is still valued for its natural dye properties and is used in various artisanal and eco-friendly dyeing processes.