Published online by Cambridge University Press: 10 May 2006
The delimitation of the genus Parmelia s.lat. has been a subject of controversy for the past 30 years. Originally this large group of lichens was split into smaller genera for convenience, based mainly on the colour of the thallus and the presence of marginal cilia (Hale 1974); later conidial and other vegetative characters were used (Hale 1984: 18–20). With time several quite small genera of parmelioid lichens were recognized by a number of authors (e.g. Elix 1994), whilst others, because of the sparsity of characters, continued to regard most of them as still belonging to Parmelia (Purvis et al. 1992). Recent molecular studies have ended this polarization, and an agreed classification is now being adopted (Blanco et al. 2004a, 2004b, 2005).