Abstract
Type specimens of Kützing’s similarly named Synedra acus (= Ulnaria acus) and Synedra arcus (= Tabularia arcus D.M. Williams, nov. comb.) are examined with light and electron microscopy. Their morphology is documented and their nomenclature and typification clarified. Comments are made on several other members of the genus Ulnaria that may be, or have been, confused with U. acus: Ulnaria schroeteri (Meister) D.M. Williams, comb. nov., and Ulnaria hunanensis Bing Liu, sp. nov. Tabularia minor (Kützing) D.M. Williams, comb. nov. (basionym: Synedra gailloni [var.] β minor Kützing) is also documented and characterized.
Acknowledgements
The authors are grateful to the following for comment: Pat Kociolek, Zlatko Levkov, Bing Liu and Matthias Schultz (Senior Curator, Herbarium Hamburgense).
Disclosure statement
No potential conflict of interest was reported by the author(s).
ORCID
DAVID M. WILLIAMS http://orcid.org/0000-0002-0584-307X
SAÚL BLANCO http://orcid.org/0000-0002-9015-2512
Notes
1 Over 40,000 records from Google search (14 May 2019).