Hypogymnia irregularis (Ascomycota: Parmeliaceae)-a new species from Asia

Hypogymnia irregularis is newly described from southwest China, Nepal, Japan, and Taiwan. Similar in growth form to H. vittata, H. irregularis differs in always lacking soredia and having staggered, lateral, or almost randomly located perforations in the lower surface. In contrast, H. vittata usually produces soredia and has perforations more centered in the lower surface and axils. Hypogymnia vittata is known from Asia, North America, Central America, and Europe, while H. irregularis is endemic to Asia. Hypogymnia irregularis is postulated as being the fertile species that is the closest living relative to the sorediate H. vittata. Another Asian species, H. stricta, can be similar in appearance to H. irregularis and H. vittata, but can be differentiated both morphologically and chemically from those two.