Abstract
A review of bryophyte records from New Zealand lakes showed a “deep‐water” assemblage occurred at ≥ 10 m depths within 16 lakes all of which possessed high water clarity (1/ K d >3). Bryophyte depth limits ranged from 12 to 70 m. Depth limit was significantly related to water clarity and extended to where the level of irradiance was 0.2–1% of light incident on the lake surface. Deep‐water bryophytes were generally absent from lakes where large populations of freshwater crayfish occurred, and from sites with physical disturbance. Between 34 and 42 bryophyte taxa were recorded, with some identifications incomplete because of unusual morphology. Although some taxa are known to be aquatic, others have previously been regarded as typically terrestrial or paludal. Deep‐water bryophytes were well represented in New Zealand lakes compared with records from elsewhere. Significant threats to this unusual plant assemblage are eutrophication accompanied by declining water clarity.