Euastrum evolutum var. perornatum A.M.Scott & Croasdale

Euastrum evolutum var. perornatum A.M.Scott & Croasdale

( Fig. 3H View FIG )

Acta Botanica Fennica 69: 32 ( Scott et al. 1965).

DISTRIBUTION. — Brazil. Amazon Basin: Scott et al. (1965); Förster (1969); Thomasson (1971, 1977); Uherkovich (1976); Martins (1986b); Melo et al. (2005, 2009); Cadima (2013). Western Amazonia (lowlands): Araujo (2003).

DESCRIPTION

Cells 65.3-67.9 µm long, 41.6-43.7 µm wide, isthmus 10.2-12.0 µm, apex 30.9-32.0 µm; cells 1.5-1.6 times longer than wide. Cells with a deep median constriction, almost completely enclosed, slightly open at the ends. Trapezoidal semicell, robust, three-lobed, interlobar deep incisions, U-shaped open; lateral and polar lobes with deep recesses in the apex; polar lobe with a deep sinus, V-shaped; apical angles with one to three spines, polar lobes narrower than basal lobes; cell wall hyaline, intramarginal granules, semicellular face with median protrusion formed by four to five granules surrounding one central granule.