Chara sp. photographed in Lake Towuti by Werner Klotz (2011).

In other parts of the series, we have presented:

Chara sp.

This is another star of the Sulawesi lakes. Sometimes called Chara sp. "red cherry" or "red flowers", although the flowers are more orange than red… and instead of being flowers, these round objects are antheridia (the singular form is antheridium), the male reproductive organs.

Chara (stonewort) is actually not a higher plant but an advanced form of algae. Stoneworts grow in fresh or brackish water worldwide, although they are not very common in most regions as they typically require clear, stagnant, and often hard water.

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In Sulawesi, we can find Chara sp. growing in all ancient lakes. We do not know whether it is one species or whether there is greater variability (at least in terms of appearance it certainly is). As these algae are typical inhabitants of oligotrophic waters and an increased supply of nutrients does not favor them, it is possible that they will disappear from some places – we are especially concerned about Lake Matano.

This photo was taken on the eastern shore of Lake Poso (2022).
Chara sp. from Lake Poso in the photo tank. It is actually quite small, although it can form large clumps. Its appearance varies in still water and in turbulent conditions (in many parts of lakes there are surprisingly large waves and water movement).
Close-up of the stonewort. Its structure resembles a higher plant, but algae do not have true leaves and stems.

Markéta Rejlková