Maney Publishing on behalf of the British Bryological Society
Abstract
The Neotropical liverwort Plagiochila retrorsa Gottsche is conspecific with P. sharpii H.L.Blomq., known previously as a Southern Appalachian endemic, as well as P. tricarinata Carl and P. permista Spruce var, subintegerrima Herzog from Costa Rica. It has been discovered recently in the Azores and Madeira, new to Europe. Illustrations, SEM micrographs of spores and elaters, nuclear magnetic resonance (NMR) fingerprints and gas chromatography-mass spectrometry (GC-MS) data are presented, based on American and European material. Costa Rican material used for an earlier phytochemical study has now also been identified as P. retrorsa. Although NMR fingerprinting initiated the present discoveries, the NMR fingerprint of P. retrorsa is not unique and NMR fingerprinting alone is not sufficient to identify the species. P. retrorsa belongs to the 9,10-dihydrophenanthrene chemotype group and the two principal secondary metabolites are 3,5-dimethoxy-9,10- dihydrophenanthren-2-ol and methyl 4-hydroxy-4'-O- methyllunularate
