Abstract
Only 3 of the 13 species so far comprised in Amphidium were retained in the genus: A lapponicum (Hedw.) Schimp., A. mougeotii (B.S.G.) Schimp. and A. tortuosum (Hornschuch) Cufodontis. Amphidium. sublapponicum (C. Müll.) Broth. is conspecific with A. lapponicum, A. cyathicarpum (Mont.) Broth., A. curvipes (C. Müll.) Broth. and A. californicum (C. Müll.) Broth. are synoymous with A. tortuosum. Amphidium brevifolium Broth., A. clastophyllum Broth. and A. papillosum Broth., all known only from the type locality, are sterile and differ vegetatively from all other species of the genus. They belong probably not to Amphidium. The types of Amphidium letestui Thér. & P. Varde, A. aloysii-sabaudiae Negri and A. remotidens (C. Müll.) Broth. could not be located.