Typification of Cocconeis lineata and Cocconeis euglypta (Bacillariophyta)

Abstract

The nominate varieties of the monoraphid diatoms Cocconeis lineata Ehrenberg and C. euglypta Ehrenberg are typified. Lectotypes of both taxa are preserved at the Ehrenberg Collection, Museum für Naturkunde, Berlin, Germany. The lectotype of C. lineata is a poorly detailed drawing, showing an ovoid valve (or frustule?) with two to three apical lines on each hemivalve. The lectotype of C. euglypta, contained in a mica, shows a unique, broadly elliptical sternum valve with up to five apical striae on each hemivalve, displaying a zigzag pattern. This is roughly consistent with the current concept of C. lineata and C. euglypta and with their usage over the last 160 years. To ensure stabilization of the names and current concepts for these two taxa, culture-based epitypes of C. lineata and C. euglypta are designated. Light and electron microscopy observations, as well as morphometric data from clones for both taxa, are presented and an amended description for each taxon is provided.

Keywords:

• lectotype
• epitype
• Cocconeis culture
• morphometric data

Acknowledgements

We gratefully acknowledge the help of Jana Bansemer with collecting and culturing diatoms, of Monika Lüchow at the SEM (both at the Botanic Garden and Botanical Museum Berlin), and of Oliver Skibbe (Berlin, Germany) for isolating and culturing. The German Federal Ministry of Education and Research (BMBF) (grants 01 LC 0026 & 01 LI 1001 A) supported the work in the Ehrenberg Collection as part of the AlgaTerra project as well as the data mobilization for GBIF. OER was partially supported by the Spanish Council of Scientific Research and by the Synthesys Project (DE-TAF-1136),which is funded by the European Community Research Infrastructure Action under the FP6 ‘Structuring the European Research Area Programme’.