Polyplacocystis ambigua, dry moss

Polyplacocystis ambigua (Penard, 1904)

Diagnosis: Periplast (20–50 μm in diameter) formed from scales with reticular external texture of distal surface. All scales bordered by a smooth or delicately ribbed rim. Scales are of three main shapes:

1) long, narrow fusiform scales with sharp-pointed apices ( Length: 7.68–14.16 μm; Breadth: 0.4–0.7; Width of rims: 0.09–0.26 μm;

2) narrowly ellipsoidal or naviculoid scales ( Length: 5.47–11.94 μm; Breadth: 0.95–2.09 μm; Width of rims: 0.11–0.33 μm;

3) broadly elliptical or oval scales with rounded poles ( Length: 3.67–9.22 μm; Breadth: 1.28–2.62 μm Width of rims: 0.14–0.38 μm).

Ecology: Freshwater, dry mosses. Not rare. Switzerland (type locality), Argentina, Canada, Chile, Germany, Japan, New Zealand, Sri Lanka, The Netherlands and Ukraine.

From Siemensma (1991)
from dry moss, Naardermeer, the Netherlands (2019)
Cysts, from dry moss, Naardermeer, the Netherlands (2019)
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