Original paper
Taxonomische Revision des Artenkomplexes um Gomphonema pumilum (Bacillariophyceae)
[Taxonomic revision of Gomphonema pumilum (Bacillariophyceae) species]
Reichardt, Erwin

Nova Hedwigia Band 65 Heft 1-4 (1997), p. 99 - 129
15 references
published: May 15, 1997
DOI: 10.1127/nova.hedwigia/65/1997/99
ArtNo. ESP050006500006, Price: 29.00 €
Abstract
Gomphonema pumilum is a diatom name which has often been used for small Gomphonema species although its real identity has been quite unknown until recently. After clearing up the taxonomic position of that taxon (Reichardt & Lange-Bertalot 1991) it became evident that there exist many similar diatoms all over the world which cannot be included in G. pumilum. They seem to grade into each other and differentiating criteria of independent taxa are hard to find. In addition, most of these diatoms show relatively uniform ultrastructure. Therefore, a taxonomic revision of such species cannot be carried out exclusively by the use of SEM. However, after intensive LM and SEM studies of a large number of samples over a wide geographic area, including type material of the relatively few species from this cluster of forms described so far (e. g. Gomphonema minusculum, G. pseudotenellum), a series of distinct species and varieties could be recognized and clearly delimited. In this paper the following taxa are described in detail: Gomphonema pumilum var. elegans var. nov., G. pumilum var. rigidum var. nov., G. micropumilum spec, nov., G. minusculum (= G. superiorensis), G. angustivalva spec, nov., G. pseudotenellum, G. geisslerae spec, nov., G. lacus-vulcani spec, nov., G. bourbonense spec, nov., G. designatum spec, nov., G. cuneolus spec, nov., and some other related taxa are discussed briefly.
Keywords
Bacillariophyceae • taxonomy • Gomphonema pumilum • diatom morphology • ultrastructure • new species