Euastrum subtrilobulatum var. laeve Kurt Först. & F.Eckert (1964: 370)

Ramos, Geraldo José Peixoto, Costa, Fabiana De Matos, Santos, Maria Aparecida Dos & Moura, Carlos Wallace Do Nascimento, 2019, Taxonomic novelties, new records, and rare species of desmids from the Chapada Diamantina region, Brazil, Phytotaxa 391 (3), pp. 185-196 : 192

Euastrum subtrilobulatum var. laeve Kurt Först. & F.Eckert (1964: 370) ( Figs 43–46 )

Cell dimensions: length 25–30 μm, breadth 20–23 μm, 4–5 μm isthmus

Habitat characteristics: River; quiet and warm waters, associated to filamentous algae.

Material examined: HUEFS 244148.

Notes: Taxon rare, reported only from the type locality in Goiás State, in central-western Brazil ( Förster 1964). It differs from the nominate variety by semicells not having a central pore. Another striking feature of this taxon is its cell wall thickening, which is quite visible on the margins in frontal view.

Figures

FIGURES 28–50. Euastrum piataense (28–34): LM (28–31), SEM (33,34), ventral view (28–30, 33), lateral view (31,34) apical view (32); Euastrum subcyclopicum var. elongatum (35–39): LM (35–38), SEM (39), ventral view (35–36, 39), lateral view (37), apical view (38); Euastrum bicudoi (40–42): ventral view (40), lateral view (41), apical view (42); Euastrum subtrilobulatum var. laeve (Figs 43–46): ventral view (43,44), lateral view (45), apical view (46); Micrasterias arcuata var. perforata (47–50): LM (47–49), SEM (50), zygospore (49). Scale bar 10 μm.