Characeae
| Stoneworts | |
|---|---|
 |
|
| Chara globularis | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Charophyta |
| Class: | Charophyceae |
| Order: | Charales |
| Family: | Characeae |
| Genera | |
Chara
Lamprothamnium
Lycnothamnus
Nitella
Nitellopsis
Tolypella
Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as "stoneworts". Linnaeus established the genus Chara in 1753.
The Charales have large, macroscopic thalli growing up to 120 cm long, they are branched, multicellular, and use chlorophyll to photosynthesize. They grow in fresh water. They may be called stoneworts, because the plants can become encrusted in lime (calcium carbonate) after some time. The "stem" is actually a central stalk consisting of giant, multinucleated cells. They are unique in having a whorl of small branchlets at each node in the stipe, this gives them a superficial resemblance to the genus Equisetum. In these whorls it is possible to see the phenomenon of cytoplasmic streaming. In fact the streaming in Chara is the fastest recorded of any cell. Cytoplasmic streaming is caused by the microfilaments found inside the cell, as proven by the use of to stop streaming.
There are about 400 species worldwide, with 33 in Britain and Ireland according to Groves and Bullock-Webster), however Stewart and Church (1992) reduce this to 21.
Characeae are the principal plant life of some of the volcanic crater lakes of Nicaragua, and can be found in excess of 20 meters depth in some circumstances. Introduced tilapia (Oreochromis niloticus) consumed all the Characeae in Lake Apoyo.
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Wikipedia