in H. G. A. Engler and K. Prantl, Nat. Pflanzenfam.215[I,3]: 460. 1902
Habitat: Crevices of neutral to acidic rock
Elevation: moderate elevations
Amphidium californicum is distinguished by the linear leaves with notched distal margins. Amphidium lapponicum has decidedly broader leaves and distal cells obscured by large, warty, cuticular papillae.