Thallus bright to deep blue-green, expanded, usually forming large, thin mats. Trichomes straight, ± parallel ... [details]

Trichomes solitary, pale blue-green, straight or slightly bent, 2-2.5 μm wide, not constricted at the granulated ... [details]

Thallus black-violet, brownish violet or dark green, fasciculate, joined into sparsely pseudobranched tufts, up to ... [details]

Thallus blackish blue-green. Trichomes nearly straight, (1.5)1.8-2(2.2) μm wide, motile with rotation, not ... [details]

Thallus fine, membranaceous, consisting of fascicle-like bundles, brigh blue-green or olive green. Trichomes up to ... [details]

Thallus dull blue-green to blackish-green. Trichomes ± straight, long, brightblue-green, sometimes olive-green, ... [details]

Trichomes blue-green, (3.4) 5-9 (11?) μm wide, regularly screw-like coiled, not or slightly constricted at the ... [details]

Thallus widely expanded, up to several (5-7) cm in length, dark blue-green or black-green, brown to yellowish ... [details]

Thallus dark green to brownish black, widely expanded, adherent, thin, firm or floating and (sometimes) ... [details]

Trichomes mostly solitary, free-floating, up to 300 μm long, straight or somewhat curved, sometimes joined to ... [details]

Trichomes straight or curved, 2-5 (5.8) μm wide (always less than 6 μm), seldom litary, mostly forming ... [details]

Trichomes straight or slightly curved, solitary, free-floating, sometimes forming purple-red (when dried violet) ... [details]

Occurrence: Freshwater, known only from the littoral of a lake; Austria (Lunzer Obersee).  [details]

Periphytic and benthic in stagnant waters, pools, lakes, also in brackish and salty waters (?), sewage polluted ... [details]

Freshwater, planktic (water-bloom-forming) and common in lakes in tropical Asia (Russia-West Siberia), India, ... [details]

Marine, on rocks or sand in the upper supra- and lower littoral and coastal zones, in mangroves, shallow bays, ... [details]

Occurrence: Freshwater, periphytic on rocks, stones, wood, hydrophytes and other substrates in flowing and stagnant ... [details]

Freshwater, planktic in lakes and ponds, often forming water blooms, widely distributed in temperate zones; Europe: ... [details]

Occurrence: Freshwater, planktic in colder lakes and stagnant waters, forming water blooms; Europe: Denmark, ... [details]

Freshwater, planktic, in mesotrophic and eutrophic, large lakes and stagnant waters, forming red water blooms; cold ... [details]

"Unrevised species." (Komárek & Anagnostidis 2005: 548) [details]