New species of Graphidaceae from the Neotropics and Southeast Asia

Descriptions and illustrations are provided for 20 new species in the family Graphidaceae (lichenized fungi) originating from El Salvador, the Guianas, Venezuela, Colombia, and Malaysia: Acanthothecis adjuncta Welz & Sipman, differing from all other Acanthothecis species by the rounded ascocarps with covered discs; Astrochapsa albella Sipman, differing from A. meridensis in the white apothecium rim, the corticolous growth habit, the more or less clear hymenium, and the protocetraric acid chemistry; A. columnaris Sipman, differing from other Astrochapsa species by the columnar marginal slips; Chapsa francisci Sipman, differing from other Chapsa species by the numerous marginal lacinae; C. nubila Sipman, differing from other Chapsa species by the combination of a guttulate hymenium and 4- to 8-spored asci; Diorygma extensum Sipman, differing from D. minisporum in producing norstictic acid instead of stictic acid; Fissurina chapsoides Sipman, a Fissurina species with large, muriform ascospores and short ascocarps opening mostly by branched slits; F. gigas Sipman, differing from F. rufula in the larger ascomata and muriform ascospores; F. vorax Sipman, differing from other Fissurina species by the aggregated ascocarps in combination with papillose paraphysis tips; Graphis murali-elegans Sipman, differing from G. elegans and G. lumbricina in the muriform ascospores; G. nigroglobosa Sipman, differing from G. mexicana in the absence of a complete thalline margin; Melanotrema comosum Sipman, a species of Melanotrema with extruding, clavate, brown hyphae on columella and excipulum; Myriochapsa annulata Sipman, differing from M. psoromica by the conspicuous, free excipulum; M. chocoensis Sipman, differing from M. psoromica in the smaller ascospores; Ocellularia pitalensis Sipman, differing from O. maxima by producing hypoprotocetraric acid; O. rugosa Sipman, similar to O. zamorana but with wider ostioles and 1-septate, pigmented ascospores with thick-walled juvenile stage; Thelotrema berendsohnii Sipman, similar to T. alboolivaceum, from which it differs by submuriform ascospores; T. kinabaluense Sipman, differing from other Thelotrema species by small, brown ascospores and protocetraric acid; T. paludosum Sipman, differing from other Thelotrema species by an inspersed hymenium, hypoprotocetraric acid and colorless, transversely septate ascospores of c. 30 x 7 mu m; and T. parvisporum Sipman, differing from T. adjectum in the small, grey-brown ascospores.