Gradsteinia torrenticola, a new aquatic moss species from Tenerife

Gradsteinia torrenticola Ochyra, Schmidt & Bultmann sp. nov. (Donrichardsia ceae), known from a single locality in a waterfall on Tenerife in the Canar y Islands, is described and illustrated. This aquatic moss is primarily cha racterized by its irregularly bi- to unistratose laminae with scattered 3-4 stratose ridges and crests giving the leaf surface an uneven and rough app earance, the single but mostly forked and spurred costa, and the leaf margi n with frequent polystratose limbidia of varying degrees of completeness. A n assessment of the relationships of this new species is troublesome due to the sterile condition of the plants. Because of the structure of the leaf laminae, it is included in the genus Gradsteinia Ochyra which, so far, is k nown only from the Colombian Andes.