Degelia, A New Lichen Genus in the Pannariaceae

Abstract

AbstractThe new genus Degelia (Pannariaceae) is described to accommodate three primarily Southern Hemisphere taxa: D. gayana (Mont.) comb, nov., D. duplomarginata (P. James & Henssen) comb, nov., and D. durietzii sp. nov. A key to the species is given, with data on synonymy, morphology, anatomy, chemistry, habitat and distribution. Coccocarpia gayana var. melacarpina Nyl. is reduced to synonymy with Degelia gayana. Relationships of Degelia with genera in the Pannariaceae and Coccocarpiaceae are discussed. Degelia is distinguished from other genera in the Pannariaceae by periclinal arrangement of cells in the upper cortex, a lower cortex of 2–3 layers of thick-walled periclinal hyphae, and Scytonema as the phycobiont; and from genera in the Coccocarpiaceae by the structure and ontogeny of the apothecia. D. duplomarginata is known from New Zealand and Hawaii, D. durietzii from New Zealand and Tasmania and D. gayana from New Zealand, Tasmania, Australia, Chile and Tristan da Cunha.