Its most famous species is lobariaceae 5 to 15 cm in diameter, with individual lobes 1.02 to 3 cm wide and up to 6 cm long. It is a foliose lichen and its leaf-like thallus is green, leathery and lobed with a pattern of ridges and depressions on the upper surface. Bright green under moist conditions, it becomes brownish and papery when dry. This species often has fine layers of hairs, a tomentum, on its lower surface. The cortex, the outer protective layer on the thallus surface, is roughly comparable to the epidermis of a green plant. The asexual reproductive structures soredia and isidia are present on the thallus surface. Minute 0.5 to 1.5 mm in diameter cephalodia—pockets of cyanobacteria—are often present on the lower surface of the thallus; these spots are conspicuously darker than the green surface of the thallus. Like other foliose lichens, the thallus is only loosely attached to the surface on which it grows.