Chara (Characeae)

Filamentous green alga with very large and long cells forming primary axes and whorls of 6-16 branches.  Reproductive structures - oogonia and antheridia - occur on the branches, but are often absent.  Chara may be distinguished from Nitella since the branches of the latter subdivide (as well as by more subtle reproductive features).  This does not occur in Chara, although smaller needle-like bract cells may occur on the branches in Chara.  A characteristic ring of even smaller sharp cells, called stipulodes, occur under the branch points in Chara. Some Chara species have corticated stems, unlike other charophytes such as Nitella.  Charophyte cells are siphonous, the stems between branch points being the length of a single long cell containing numerous chloroplasts and nuclei.

Typical habitats

Found in slow flowing streams and lakes; generally characteristic of clean water. The disappearance of charophytes from lake beds is a symptom of water quality degradation.

Classification