Cymbella affinis var. neoprocera W.Silva, comb. nov. et, 2015

Silva, Weliton Jose da, Jahn, Regine, Ludwig, Thelma Alvim Veiga, Hinz, Friedel & Menezes, Mariangela, 2015, Typification and taxonomic status re-evaluation of 15 taxon names within the species complex Cymbella affinis / tumidula / turgidula (Cymbellaceae, Bacillariophyta), PhytoKeys 53, pp. 1-25 : 4-5

Cymbella affinis var. neoprocera W.Silva, comb. nov. et nom. nov. Figs 22-28

Basionym.

Cymbella excisa var. procera Krammer, Diatoms Europe 3: 159, Figs 9:1-7, 2002 (Figs 22-28).

Holotype.

Preparation 212A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

Lectotype

(designated here). An individual on preparation 212A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany; represented by Fig. 22 .

Type locality.

Germany, Eifel, Totenmaar, 22.2.1974.

Valvae dorsiventral, dorsal margin broadly convex, ventral margin straight; ends not protracted, rounded, or subrostrate to rostrate; length 21.5-41.0 µm, breadth 8.0-11.0 µm, L/B ratio 2.7-4.0; axial area narrow, linear-arched, indistinct central area; striae 9-13 in 10 µm, becoming 11-14 toward ends, one isolated pore at end of central striae on ventral side; 22-27 punctae in 10 µm.

Remarks.

The combination of Cymbella excisa var. procera with Cymbella affinis would be illegitimate unless it was given a new name, because it would be a later homonym of Cymbella affinis var. procera Krammer. Specimens designated by Krammer (2002), i.e., the preparation 212A IOK (BRM), were found to belong to more than one taxon therefore to clarify the taxonomy we designated a lectotype as established in Art. 9.11 of the ICN ( McNeill et al. 2012).

A broader range of metric characteristics were highlighted in this study compared to the characterization of the type population ( Krammer 2002, p. 28). We find smaller (21.5-41.0 vs. 24-41 µm) and narrower (8.0-11.0 vs. 8.4-11.0 µm) representatives of this taxon compared to the Krammer’s (2002) records. Still considering Krammer’s (2002) findings, we observe more densely striated (9-13 vs. 9-11 striae in 10 µm) and less punctate (22-27 vs. 24-27 punctae in 10 µm) valves.

Figures

Figures 1 - 28. Cymbella affinis species complex 1 - 7 Cymbella affinis Kuetz. var. affinis 8 - 14 Cymbella affinis var. excisa (Kuetz.) Grunow, specimens from Trieste in preparation BM 18543 11 Lectotype, designated here 15 - 21 Cymbella affinis var. excisa [- Cymbella excisa sensu Krammer], specimens from Trieste in preparation 1131 IOK 16 Isolectotype, designated here 22 - 28 Cymbella affinis var. neoprocera W. Silva, specimens from Germany in preparation 212 A IOK, holotype 22 Lectotype, designated here. Scale bar: 10 µm.