Roccella tinctoria is a lichen that grows on rocks and trees, primarily in coastal regions. It is known for its ability to produce natural dyes, particularly a reddish-purple color called orchil. This dye has been used historically in textiles and art. The lichen contains compounds called orcinol and pulvinic acid, which are responsible for its dyeing properties. Roccella tinctoria is harvested, dried, and processed to extract the dye, making it a valuable resource in traditional dyeing practices. Its use has declined with the advent of synthetic dyes, but it remains important in natural dyeing communities.