junction

Description:

Tolypothrix (toll-eep-o-thricks) is a filamentous blue-green alga (cyanobacterium) which expresses false branching, i.e., the cells divide in one plane only, but a heterocyst may cause cells to break free and form an apparent branch. Heterocysts are differentiated thick-walled cells that provide the site for nitrogen fixation. In this image, the empty-looking heterocyst is located within the trichome and has a rectanglular shape. Differential interference microscopy.

data on this strain.