Physcia is a genus of lichenized fungi commonly found in the Comunidad Valenciana and other regions with similar climates. This genus includes a variety of species, frequently seen as greyish rosettes on tree barks, rocks, and sometimes even man-made structures.

Locally known simply as "liquens," these fungi play a vital role in the ecosystem, contributing to biodiversity and serving as indicators of environmental health. They can often be observed in areas with good air quality, as they are sensitive to pollution levels.

• Appearance: Physcia lichens typically appear as small, leaf-like structures. They often have a greyish color with a potential bluish or greenish tint, depending on the moisture and light conditions.
• Growth Habit: These lichens form rosettes that adhere closely to their substrate, which can be a variety of surfaces such as tree bark, rocks, and walls.
• Habitat: Physcia species are versatile and can inhabit both urban and rural environments, thriving in areas where they receive adequate sunlight and moisture.

These lichens not only add to the natural aesthetic of the region but also provide critical ecological functions such as nutrient cycling and offering habitats for various microorganisms and small insects.