Staurophora soodensis (Krasske) Bahls, 2013

Bahls, Loren, 2013, New diatoms (Bacillariophyta) from western North America, Phytotaxa 82 (1), pp. 7-28 : 10

Staurophora soodensis (Krasske) Bahls , comb. nov. ( Figs 7–12 )

Basionym: — Navicula soodensis Krasske (1927 , Diatomeen deutscher Solquellen und Gradierwerke. Archiv für Hydrobiologie 18: p. 272, pl. 10, figs 20–22). Holotype: GERMANY: Solquellen, A III 4, KASSEL (Lange-Bertalot et al. 1996).

Synonyms: — Stauroneis soodensis (Krasske) Cholnoky (1962: 47) ; Stauroneis legleri Hustedt (1959a: 793 , fig. 1138; 1959b: 418, figs 5–7) (designated a synonym by Krammer & Lange- Bertalot 1986: 233).

Voucher: — USA, Montana: Sheridan County, White Lake , 48.5834 o N, 104.1176 o W, elev. 598 m, coll. R. Apfelbeck, 31 May 1994. MDC sample 141901; MDC slide P3-15-9 ( Figs 7–12 ). MONTU !

Observations: —From salt springs in Germany, Krasske (1927) described valves of Navicula soodensis as 20–26 µm long by 5 µm wide with 18 striae in 10 µm. Valves from a hypersaline lake in Montana ( Figs 7–12 ) are 22–33 µm long and 4.4–8.8 µm wide with 16–20 striae in 10 µm. The highly arched valves ( Fig. 9 ), finely punctate striae, and saline water habitats of this species indicate that it belongs in the genus Staurophora . Staurophora tackei (Hustedt) Bahls (2012b: 36) has a higher stria density (24–26 in 10 µm at valve center, up to 32 in 10 µm near the apices).

Ecology: — White Lake , Sheridan County, Montana has a pH of 10.0 and a specific conductance of 87000 µS/cm .

Family Cymbellaceae Greville 1833: 263 , 409

Genus Cymbella C. Agardh 1830: 1

Figures

FIGURES 1–12: Staurophora columbiana, Staurophora soodensis. Figs 1–6: Staurophora columbiana. Figs 1, 2, 3, 6: Kingsbury Lake, Chouteau County, Montana (type locality). Fig. 1: Holotype specimen. Figs 4, 5: Hailstone National Wildlife Refuge, Stillwater County, Montana. Fig. 4: Janus valve. Figs 7–12: Staurophora soodensis from White Lake, Sheridan County, Montana. Fig. 9: Girdle view. Scale bars: 10 µm.