The affinities of Costesia and Neosharpiella and notes on the Gigaspermaceae (Musci) [Nomenclature; Mexico; South America]

The genera Costesia Thér. and Neosharpiella Robins. & Delg. are transferred from the Funariaceae to the Gigaspermaceae. Neosharpiella turgida (Mitt.) Robins. & Delg. is reported for the first time from Chile. The morphology of the six genera currently placed in the Gigaspermaceae is compared and generic inter-relationships discussed. SEM micrographs of the spores of four genera are given. In the revised sense presented, the Gigaspermaceae have a widely scattered, predominantly Southern Hemispheric distribution. Nomenclatural notes on several taxa are appended and several lectotypes are proposed.