Gradsteinia torrentfcola, a new aquatic moss species from Tenerife

Abstract Gradsteinia torrenticola Ochyra, Schmidt & Bultmann sp. nov. (Donrichardsiaceae), known from a single locality in a waterfall on Tenerife in the Canary Islands, is described and illustrated. This aquatic moss is primarily characterized by its irregularly bi- to unistratose laminae with scattered 3–4 stratose ridges and crests giving the leaf surface an uneven and rough appearance, the single but mostly forked and spurred costa, and the leaf margin with frequent polystratose limbidia of varying degrees of completeness. An 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 known only from the Colombian Andes.