Taxonomic studies of the diatom genus Halamphora (Bacillariophyceae) from the mountainous regions of southwest China, including the description of two new species
Author
You, Qingmin
College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
Author
Kociolek, John Patrick
Author
Wang, Quanxi
College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
text
Phytotaxa
2015
2015-04-15
205
2
75
89
http://dx.doi.org/10.11646/phytotaxa.205.2.1
journal article
10.11646/phytotaxa.205.2.1
1179-3163
13639728
Halamphora montana
(Krasske) Levkov
(
Figs. 66–77
)
Description:—
Valves semi–lanceolate, dorsiventral with smoothly convex dorsal margin and slightly convex ventral margin. Valve ends narrowly rounded to subcapitate and deflected ventrally. Length 13.3–18.0 μm, valve breadth 3.3–3.6 μm. Externally, the raphe is weakly arched and both proximal and distal raphe ends are deflected or curved towards the dorsal margin of the valve (
Figs. 71, 73, 76
), proximal raphe ends slightly expanded (
Fig. 76
). With narrow dorsal raphe ledge, slightly elevated from the valve face (
Figs. 71, 73, 76
). Axial area narrow. The central area is a broad fascia on both valve sides. Beneath the raphe ledge the areolae appear to be slightly larger and lie in a shallow depression (
Fig. 76
). Striae slightly radiate throughout, 45–50/ 10 μm, difficult to resolve with LM. Internally, the proximal raphe ends terminate at a narrow central helictoglossae (
Figs. 72, 77
). Distally, the internal raphe ends terminate as helictoglossae (
Fig. 75
).
Distribution and ecology:—
Hezhang,
Guizhou
,
China
, altitude
1450 m
a.s.l., pH 7.2, collected from a pond near the road, with many filiform green algae in the water.