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Summary Article: charophytes
From Dictionary of Microbiology & Molecular Biology

A group of macroscopic green algae variously regarded as (a) a distinct division (Charophyta) [e.g. Book ref. 123, pp. 303–330]; (b) a class (Charophyceae) within the division Chlorophyta [e.g. Book ref. 130, pp. 36–132]; or (c) an order (Charales) within a class, Charophyceae, which is broader than that in (b): see CHLOROPHYTA. Charophytes (e.g. Chara and Nitella) have several features in common with bryophytes (mosses and liverworts): e.g., the plant is structurally complex, being differentiated into root-, shoot- and leaf-like structures; the shoots are divided into nodes (each node bearing a whorl of branches) and internodes; sexual reproduction is oogamous, and an envelope of sterile cells (shield cells) surrounds the antheridia and oogonia; asexual reproduction may occur e.g. by the formation of bulbils (‘plantlets’) on the rhizoids, or of AMYLUM STARS on the lower nodes, but apparently never by the formation of zoospores. Charophytes are generally heavily calcified (hence the popular names ‘stoneworts’ or ‘brittleworts’); they occur mainly in fresh water (lakes, ponds, etc). (See also GYROGONITES.)

Copyright © 2006 John Wiley & Sons Ltd.

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