X. parietina, also known locally as maritime sunburst lichen, is one of the most common lichen species observed in urban parks and treed spaces in the Pacific Northwest. The vegetative body of the lichen (thallus) is foliose in form, meaning its shape is lobed or leaflike. The upper surface is often a bright, cheerful yellow but it can also be orange or a greenish yellow. While it does grow on rocks, I find it more often growing on hardwood branches near, or over, water. This lichen in particular appears fairly tolerant of air pollution and seems to have adapted easily to urban green spaces.

For optimal dye potential, the recommended length of time to ferment X. parietina (i.e., from harvest to use) is approximately 12 weeks/3 months. This vat on the other hand had been left to ferment for approximately 16 months, so please note that deeper colours than these below are possible. Let’s just vaguely blame the pandemic and move on.

Note: I was first introduced to the dye potential of this species through both Lichen Dyes: The New Source Book by Karen Diadick Casselman and a mushroom dyeing workshop with Alissa Allen (Mycopigments).

TL:DR: Baby blue and cotton candy pink are possible with this cheerful lichen through a fermentation process and access to sunlight. If trying this out yourself, pick a sunny, summer day for best results.