A world monograph of the lichen genus Gyalectidium (Gomphillaceae)

Seventeen new species of Gyalectidium have been discovered in various parts of the world, and those unexpected findings formed the starting point for a survey of the taxonomy and ecogeography of the genus. The following species are described as new in this paper: G. areolatum Ferraro & Lacking (Neotropics), G. atrosquamulatum Lacking & Kalb (Kenya), G. australe Lacking (Australia), G. conchiferum Lacking & Wirth (Chile), G. denticulatum, Lacking (Costa Rica), G. fantasticum Ferraro & Lacking (Neotropics), G. flabellatum Serus. (Australasia), G. fuscum Lacking & Serus. (Africa and Papua New Guinea), G. gahavisukanum Serus. (Papua New Guinea), G. kenyanum, Lacking & Kalb (Kenya). G. laciniatum Lacking (Costa Rica), G. maracae Lacking (Neotropics), G. membranaceum Serus. & Lacking (Canary Islands), G. minus Serus (Canary Islands and southern Italy), G. novoguineense Serus. (Australasia), G. puntilloi Serus. (south-west Europe), and G. verruculosum Serus. (Australasia). Calenia microcarpa Vezda [Syn.: Bullatina microcarpa (Vezda) Brusse] is included in Gyalectidium as G. microcarpum (Vezda) Lacking, Serus. & Vezda comb. nov., and G. catenulatum (Cavalc. & A. A. Silva) Ferraro, Lacking & Serus. is treated as a species different from G. filicinum. Gyalectidium corticola Henssen is transferred to Calenia as Calenia corticola (Henssen) Ferraro, Lacking & Serus. comb. nov. A key to all 29 accepted species of Gyalectidium is provided. The infrageneric phylogeny is constructed by means of a phenotype-based cladistic analysis, and the systematic affinities of the genus are discussed, accompanied by notes on the distribution and ecology of the species. Apothecia are not yet known in several species, including new ones. (C) 2001 The Linnean Society of London.