Resolving the genus Graphina Mull. Arg. in North America: new species, new combinations, and treatments for Acanthothecis, Carbacanthographis, and Diorygma

As part of our ongoing studies of the Graphidaceae in North America, we resolve the status of all taxa traditionally assigned to the genus Graphina that have been reported from the continent north of Mexico. Treatments for the North American members of Acanthothecis, Carbacanthographis, and Diorygma are presented because several species of Graphina have been reassigned to these genera, and our studies of accumulated herbarium materials revealed the existence of several previously unreported and unrecognized species. The following new combinations are made: Acanthothecis leucopepla, A. mosquitensis, A. peplophora, and A. poitaeoides. Carbacanthographis muriformis is described as new to science based on material from Florida. The following taxa are reported from North America for the first time: Acanthothecis poitaeoides, Diorygma junghuhnii, D. reniforme.