Micrasterias radiosa var. elegantior (G.S.West) Croasdale

Micrasterias radiosa var. elegantior (G.S.West) Croasdale

( Fig. 5D, E View FIG )

A synopsis of North American desmids Part II. Desmidiaceae: Placodermae, Section 2: 181 ( Prescott et al. 1977). — Micrasterias sol var. elegantior G. S. West, Mémoires de la Société des Sciences Naturelles de Neuchâtel 5 (2): 1035 ( West 1914). — Micrasterias radiosa f. elegantior (G. S. West) G. M. Smith , Bulletin of the Wisconsin Geological and Natural History Survey 57 (2): 164 ( Smith 1924).

Micrasterias radiosa var. ornata Nordstedt, Videnskabelige meddelelser fra Dansk naturhistorisk forening i Københaven 21 (14-15): 223 ( Nordstedt 1870). — Micrasterias radiosa f. ornata (Nordstedt) Kurt Förster, Algological Studies / Archiv für Hydrobiologie, Supplement 28: 246 ( Förster 1981).

DISTRIBUTION. — Cosmopolitan. Amazon Basin: Thérézien (1986); Cadima (2013). As M. radiosa var. ornata f. elegantior : Förster (1969). As M. radiosa var. ornata f. ornata : Martins (1986b). Western Amazonia (lowlands): Duque & Núñez-Avellaneda (2000) and Núñez-Avellaneda (2008) as M. radiosa var. ornata f. ornata .

DESCRIPTION

Cells 251.8-262.0 µm long, 238.1-265.1 µm wide; isthmus 23.6-28.0 µm; apex: 41.0-43.0 µm; cells 1.15 times longer than wide. Cells with a deep median constriction, semiopen median sinus; ornamented cell wall with intramarginal denticles arranged along half of the basal margins of each semicell. Semicircular semicells, five-lobed, apical lobe subrectangular, elongated, apical margin chamfered in median region,extremities two-denticulated, lateral and basal lobes elongated, V-shaped, similar to each other, divided into lobes two-denticulated.