Bibliographic Detail

Lange-Bertalot, H. & Ulrich, S., 2014

Reference:
Lange-Bertalot, H. & Ulrich, S. (2014). Contributions to the taxonomy of needle-shaped Fragilaria and Ulnaria species. Lauterbornia 78: 1-73, 30 pls, 2 tables.

Abstract:
The goal of this paper is to improve taxonomy and applicability of needle-shaped freshwater diatoms belonging to the genera Fragilaria and Ulnaria in practical biological water assessment. Samples from ca. 25 German lakes and rivers, with special emphasis on Saxony, were investigated with light microscopy and scanning electron microscopy. In addition, historic documents as well as original slides and type material from different authors were involved to compare with recent Fragilaria/Ulnaria morphodemes. 14 Fragilaria and 1 Ulnaria taxa (species, subspecies and varieties), most of them abundant in Germany, are characterized morphologically and discussed in their taxonomical context. Among them are 7 new taxa, three existing, but now differently classified taxa and two species that are historically documented, but not well known. A short determination key and a classification of the taxa according to their determinability in a counting chamber and in a diatom slide are given. In addition, the neotypification of Synedra acus Kützing and the epitypification of Bacillaria ulna Nitzsch are proposed based on suitable historic material. Specimens of the type populations of both species are compared with recent morphodemes.