Analysis of the type of Synedra acus var. ostenfeldii (Bacillariophyta) and its transfer to the genus Fragilaria

Bart Van de Vijver, Elizabeth E Alexson, Euan D. Reavie, François Straub, Gunnar Steinn Jónsson, Luc Ector

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


The type material of Synedra acus var. ostenfeldii Willi Krieg. was investigated using light and scanning electron microscopy. The species is one of the few fragilarioid taxa that forms stellate colonies. Its morphology was compared with that of Fragilaria tenera var. lemanensis Druart, Lavigne & M.Robert, another taxon forming star-shaped colonies, on the type slide and in material from a neighbouring lake. The results show both taxa not being conspecific based on valve outline, valve dimensions and presence of spines. Based on the observations, Synedra acus var. ostenfeldii is transferred to the genus Fragilaria as F. ostenfeldii (Willi Krieg.) Van de Vijver, Alexson & Reavie comb. nov. stat. nov. whereas F. tenera var. lemanensis is raised to species level as Fragilaria lemanensis (Druart, Lavigne & M.Robert) Van de Vijver, Ector & Straub stat. nov. Brief notes on their ecology are added.

Original languageEnglish (US)
Pages (from-to)85-95
Number of pages11
JournalBotany Letters
Issue number1
StatePublished - Nov 23 2020

Bibliographical note

Publisher Copyright:
© 2020 Société botanique de France.


  • Diatom plankton
  • Fragilaria
  • morphology
  • taxonomy
  • type material


Dive into the research topics of 'Analysis of the type of Synedra acus var. ostenfeldii (Bacillariophyta) and its transfer to the genus Fragilaria'. Together they form a unique fingerprint.

Cite this