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Novis P.M., Lorenz M., Broady P.A. and Flint E.A. 2010. Parallela Flint: its phylogenetic position in the Chlorophyceae and the polyphyly of Radiofilum Schmidle. Phycologia 49: 373–383. DOI: 10.2216/09-65.1 Analysis of chloroplast protein sequences from the genes atpB, rbcL and psaB demonstrates that the ribbon-forming freshwater alga Parallela novae-zelandiae is a member of the Chlorophyceae. We reject earlier classifications of Parallela as a member of the Tetrasporales or Gloeotilales and also confirm the splitting of the latter order. Molecular analysis shows that it is closely related to Radiofilum transversale but not R. conjunctivum, the latter associating with green algae having counterclockwise-displaced flagellar apparatuses. Since R. conjunctivum is the type species of the genus, we refer R. transversale to Parallela transversale. The two species of Parallela share a ribbon-forming mucilaginous habit and an absence of pyrenoids and layered mucilage. Parallela novae-zelandiae differs fr...

The unicellular, sessile and setate green alga Dicranochaete reniformis Hieronymus has been referred to the orders Tetrasporales, Chlorococcales and Chaetophorales. Ultrastructural investigation of the alga points to a pseudocilial nature of the seta and reveals the occurrence of a contractile vacuole near the base of the seta. These observations suggest a classification of this taxon within the Tetrasporales. We are, however, of opinion that this order as presently conceived, is insufficiently characterized to be considered a natural group. The pyrenoid of Dicranochaete reniformis possesses cytoplasmic invaginations of a type not previously recorded among tetrasporalean algae. The possible taxonomic significance of this character is discussed.

Vegetative cells of Chaetopeltis sp. were examined by electron microscopy to ascertain the ultrastructure of the pyrenoid. Unlike other algal pyrenoids described to date possessing cytoplasmic canaliculi, the pyrenoid of Chaetopeltis is completely traversed by the chloroplast envelope. Located in the cytoplasmic channel dividing the plastid and pyrenoid is a unique disc-like double membrane.

Two new species of Sphaerellocystis (Chlorophyta: Tetrasporales: Hypnomonadaceae) are described from northwestern Moravia: S. stigmatica and S. globosa.