The scales of Peyssonnelia squamaria are spherical, uneven, and flat. Sometimes many scales cover one another after emerging from a shared holdfast. The algal surface is bright and frequently features rounded lines that are closer together and parallel lines that are farther apart. Similar to the rings in higher plants, the rounded lines identify years of faster growth. The thin, multicellular rhizoids that form on the underside of the algae are represented by the straight lines. In addition to helping the alga stick to a substrate, the rhizoids give the ringed lines a paler hue. The scales vary in diameter, but they often measure two to three centimeters. The algae has a vivid blood red hue. Some people might have an orange inclination.