Macromitrium Brid., one of the richest moss genera in New Caledonia, has not so far been revised. In the vicinity, only New Zealand, Australia and Papua New Guinea have benefited from a comprehensive overview of Macromitrium species. A review of the morphological characters of the types, completed by many fresh specimens collected since 2000, enables to clarify the relationship between the 46 taxa inherited from past and present bryological contributions since 1857 and to define five main morphological patterns among the Macromitrium species in New Caledonia. Taxonomic treatment includes synonymies, typifications, descriptions, ecological and geographical features. Eventually 24 taxa are accepted at specific or infraspecific rank. Among them, 14 are locally endemic, including three varieties.
Orthotrichaceae, morphology, musci, New Caledonia, lectotypification, new combination