Asterionella Hassall (Heterokontophyta, Bacillariophyceae) Taxonomic history and quantitative methods as an aid to valve shape diffrentiation

Abstract

The taxonomic history of the diatom genus Asterionella is sketchy at best. At present, delimitation of the genus, and species within it, are unclear. This is presented in a compilation of the taxonomy of Asterionella. In regard to species determination, valve shape variation is important. With the proliferation of splitting diatom taxa at the species level, the need for revision of Asterionella is apparent. We have provided some initial results concerning application of quantitative methods to valve shape variation in Asterionella. Seven shape variants may be present in the Great Lakes.