Anabaena Bory
	From Greek anabaino, "to rise"
Heterocysts allow for nitrogen fixation.	Anabaena has uniseriate, straight, curved, or coiled trichomes that may be constricted at the cell walls. The blue-green to yellow-green colored cells may be spherical, ellipsoidal, cylindrical, or bent, but overall look much like a string of beads. Some species have soft and colorless mucilage.   Groups of gas vesicles provide bouyancy in eutrophic or turbid waters for planktonic species. Intercalary, solitary heterocysts for nitrogen fixation are spaced fairly regularly along the filament. The akinetes are also intercalary, solitary or in groups of 2-5, are spherical, ellipsoidal, cylindrical, or curved in shape, and are sometimes found adjacent to the heterocysts.   Anabaena is similar in morphology to Nostoc, but has looser, more indistinct mucilage, filaments that are less constricted, akinetes in different locations, more motile hormogonia, and a different habitat.   The mucilage envelope can be seen when the filaments are stained with India Ink (above).