On the ultrastructure of Chamaepinnularia schauppiana Lange-Bertalot & Metzeltin (Naviculaceae s. l.)

The species Charnaepinnularia schauppiana was described in 1996 on the basis of LM observations. An investigation of specimens using the SEM was, however, considered necessary to be completely sure about the allocation of the new species to Charnaepinnularia. These SEM observations were carried out during an investigation of materials sampled from shallow pools in the Danta di Cadore mires (south-eastern Alps, Italy). SEM micrographs allowed a detailed description of the ultrastructure (in particular, the peculiar grooves on the axial and central area, and the sub-marginal position of the silica bridges dividing the striae into two foramina), and definitively confirming the genus allocation. Moreover, useful information on habitat and substrata preference of this rather rare species was also provided.