Studies on type material from Kützing’s diatom collection I: Synedra vitrea Kützing, with comments on Ulnaria fragilariaeformis (F.E. Fritsch and M.F. Rich) D.M. Williams, nov. stat. et nov. comb. and Ulnaria undulata (Rabenhorst) D.M. Williams, nov. stat. et nov. comb.

ABSTRACT

Original material of Ulnaria (Synedra) vitrea has been examined using light and electron microscopy. Valve and girdle morphology are documented, comments are made on various synonyms and other published, named varieties of Synedra vitrea. As Synedra vitrea is often considered a synonym of Ulnaria amphirhynchus or Ulnaria ulna var. amphirhynchus, two additional taxa are discussed: Ulnaria fragilariaeformis (F.E. Fritsch and M.F. Rich) D.M. Williams, nov. stat. et nov. comb. and Ulnaria undulata (Rabenhorst) D.M. Williams, nov. stat. et nov. comb. Both were previously considered to be varieties of Ulnaria amphirhynchus (basionym: Synedra amphirhynchus Ehrenberg). Ulnaria amphirhynchus has not yet been studied in detail. The characters of the genus Ulnaria are outlined once again and discussed with respect to characterising taxa (of whatever rank) rather than, or in addition to, describing them.

KEYWORDS:

• New combinations
• type specimens
• valve
• girdle morphology
• Ulnaria

Acknowledgments

Synthesys grant FR-TAF-6729 allowed me to study the diatom collections in Muséum National d’Histoire Naturelle, Paris (PC). Line Le Gall, Curator of Algae at PC, was of invaluable assistance in guiding me through their collections. The NHM provided funds to visit the herbarium in Università degli Studi di Roma La Sapienza (RO) to examine, among other material, specimens in the diatom collection of Giuseppe de Notaris (1805–1877).

I am grateful to Luc Ector (Luxembourg Institute of Science and Technology (LIST), Department of Environmental Research and Innovation, Belvaux, Luxembourg) for providing numerous references to published records of Synedra vitrea, to Bart Van de Vijver (Meise Botanic Garden, Meise, Belgium) for a copy of Kinker’s Catalogue and to Pat Kociolek (Department of Ecology and Evolutionary Biology University of Colorado, Boulder, Colorado, USA) for his usual broad range of valuable and insightful comments on an earlier version of this ms.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Notes on contributors

David M. Williams

David M. Williams is a diatomist at the Natural History Museum, London (BM). He has authored nearly 200 papers and 10 books, mostly on diatom taxonomy, systematics and biogeography, as well as on systematic and biogeographic theory.