Pinnularia aljustrelica sp. nov. (Bacillariophyceae), a new diatom species found in acidic waters in the Aljustrel mining area (Portugal) and further observations on the taxonomy and ecology of P. acidophila Hofmann et Krammer and P. acoricola Hustedt - Luís, Ana T.; Novais, Maria Helena; Van de Vijver, Bart; Almeida, Salomé F.P.; Ferreira da Silva, Eduardo A.; Hoffmann, Lucien; Ector, Luc (2012)