Nitella tenuissima (Desv.) Kuetzing

Plant small, tufted, less than 8 cm in length, with several branches arising from a single basal node, branches of unlimited growth, branching regular and symmetrical (1); no stipulae below the laterals (2,4); a dactyle which is located on the terminal branches shows two cells in the apex (3; magnified the circle of 2); sex organs monoecious (4); the oogonia below the antheridia (4) spherical or broadly elliptic, 220 micrometer long x 128 micrometer in width, invested by corticating cells that show 8-9 turn (6) antheridia terminal and vertical on a branchlet in the furcations (branch forks) (4), sometimes forming bundles on a branchlet (2), silver gray, 140-360 micrometer in diameter, non-compartmentalized gray shield cells (5). There is no cell wall ingrowth in the shield cell (outer layer cell) and thus no compartmentalization.

This species is known from shallow water on silty bottoms, mostly in soft water or slightly acid lakes in Wisconsin and Michigan but on muddy sediments in the Connecticut River.