The importance of the anatomy and fine morphology of reproductive structures for the systematics of the family Parmeliaceae is highlighted by the new genus Notoparmelia, described here for Australasian species of Parmelia. These species were known to form a monophyletic lineage but correlated characters for its delimitation were lacking. A major characteristic used here for the circumscription of this genus is the overlooked apothecial anatomy. The proper exciple is reduced to one layer formed exclusively by large hyphae without any clear branching pattern and embedded in an abundant polysaccharide matrix. This feature differs from the rest of Parmeliaceae which have a stratified three-layered proper exciple composed of a thin hyaline layer, intermediate layer and basal cortex-like structure. The anatomy of proper exciple, together with the thickness of spore walls and other morphological characters such as lobe morphology, pseudocyphellae and rhizine type, allow a precise diagnosis of the new genus. The area of distribution is also useful for characterizing this genus. Sixteen new combinations are proposed.
