Encyonema hamsherae Winter & Bahls, 2013

Winter, Diane & Bahls, Loren, 2013, Encyonema hamsherae, a new diatom species from the Northern Rocky Mountains, USA, Phytotaxa 127 (1), pp. 58-65 : 61-63

Encyonema hamsherae Winter & Bahls sp. nov. ( Figs 3–16 )

Valvae parce usque ad valde dorsiventrales. Labrum dorsuale curvum, labrum ventrale leviter convexum, termini porrecti et leviter capitati. Raphe recta, termini proximi leviter dorsuali modo deflexi, termini distales valde ventrali modo deflexi. Axialis area angusta, media area leviter extensa, stigma absens. Mediae striae leviter radiales evenientes paene parallelae ad terminos. Valva 19–30 µm longa, 6.5–7.5 µm lata, dorsuales mediae striae (14) 16– 18 per 10 µm, ventrales mediae striae (11) 15–17 (18) per 10 µm.

Valves moderately to strongly dorsiventral. Dorsal margin arched, ventral margin slightly convex, ends protracted and slightly capitate. Raphe straight, proximal ends slightly dorsally deflected, distal ends strongly ventrally deflected. Axial area narrow, central area slightly expanded, stigma absent. Striae slightly radiate in center becoming nearly parallel at ends. Valve length 19–30 µm, valve width 6.5–7.5 µm, dorsal central striae (14) 16–18 in 10 µm, ventral central striae (11) 15–17 (18) in 10 µm.

Type:— USA. Montana: Madison County, Shovel Creek , 44 o 50’ 38” N, 111 o 59’ 43” W, composited periphyton sample collected 18 September 2002, collected by Al Nixon , Montana DEQ, ( Circled specimen ( Fig. 3 ) on slide 15–94 , Montana Diatom Collection sample number 263001(1) ( MONTU!), holotype, designated here; circled specimen on slide T4-11 - 7 , Montana Diatom Collection sample number 263001(1) ( MONTU), isotype, designated here ).

Habitat:— Lotic sites in northern Wyoming and western Montana Distribution:—montane northwestern United States

Etymology:—Dedicated to Dr. Sarah Hamsher

Other Information:—Collected 18 September 2002; composited periphyton sample; collected by Al Nixon, Montana DEQ; Environmental data: specific conductance = 359 µS/cm; pH = 8.74; total alkalinity = 176 mg /L; temperature = 10.4 C; dissolved oxygen = 11.41 mg /L; total phosphorus = 0.006 mg /L; nitrate + nitrite = 0.05 mg /L.

Figures

FIGURES 3–20: Figures 3–16, Encyonema hamsherae sp. nov. Figures 17–20. Encyonema hebridicum. Figs 3 (holotype), 4, 7, 8, 10–13. Shovel Creek, Montana; Figs 5, 9. Castle Creek (Stillwater), Montana; Fig. 6. Tongue River, Wyoming; Figs 14–16. Trout Creek, Montana; Figs 17, 18. Kootenai Fen, Glacier National Park, Montana (MDC sample # 451707 (1), University of Montana Herbarium (MONTU) accession #39–85); Figs 19, 20. (isotype) Lulea Lappmark, Sweden (Cleve and Möller Nr. 37), Fig. 20 shows two focal planes of same valve. Scale bars are 10 µm unless otherwise noted.