Lyngbya majuscula Harvey ex Gomont

Thallus widely expanded, up to several (5-7) cm in length, dark blue-green or black-green, brown to yellowish brown. Filaments very long, often strongly curved or wavy, rarely slightly coiled. Sheaths colourless, when young thin, unlarnellated, later very wide, lamellated, outside rough, up to 15 um thick. Trichomes cylindrical, blue-green, blackish, dull-green, brownish green or grey violet to reddish violet, 15-20-40-60 (80?) urn wide, not constricted at the ungranulated cross-walls, not attenuated at the ends. Cells very short, discoid, 1/6—1/15x as long as wide, 2-4 (8) um long; apical cells rounded, without calyptra.
Marine, on rocks or sand in the upper supra- and lower littoral and coastal zones, in mangroves, shallow bays, sometimes on macroalgae, rarely floating, distributed worldwide, pantropical species, possibly cosmopolitan, but surely not in cold seas; sometimes grows in massive mats (registered mainly in northern and eastern Australia, Indonesia, and SE Africa - Zanzibar); records from tropical and subtropical freshwaters, and moist soils among mosses near thermal springs, represent evidently other special species; (compare L. latissima, I. magnified and others). (Komárek, Anagnostidis, 2005).