Typification and taxonomy of Gyrosigma tenuissimum (W. Sm.) J.W. Griffith & Henfr., comparison with Gyrosigma coelophilum N. Okamoto & Nagumo and description of two new taxa: Gyrosigma tenuissimum var. gundulae var. nov. and Gyrosigma baculum sp. nov. (Pleurosigmataceae, Bacillariophyta)

Document Type

Article

Date of Original Version

6-13-2014

Abstract

Gyrosigma tenuissimum (W.Sm.) J.W.Griffith & Henfr. was examined in the original material and an emended description is presented. Its protologue contains an error of taxonomic significance: in the type material, the valve and raphe sternum do not show the considerable flexure described and illustrated in Smith (1853). A comparison with Gyrosigma coelophilum N. Okamoto & Nagumo revealed that the latter, although similar in several characters, differs sufficiently in others to warrant separate specific status. Descriptions of two new taxa are given: Gyrosigma tenuissimum var. gundulae var. nov. and Gyrosigma baculum sp. nov. Both show very fine longitudinal striae at or beyond the limit of ordinary light microscopy and are practically non-sigmoid. © 2014 Magnolia Press.

Publication Title, e.g., Journal

Phytotaxa

Volume

172

Issue

2

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