Star candlestick alga
| Star candlestick alga | ||||||||||||
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Star candlestick alga ( Nitellopsis obtusa ) |
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| Scientific name | ||||||||||||
| Nitellopsis obtusa | ||||||||||||
| J. Groves , 1919 |
The star candlestick alga ( Nitellopsis obtusa ) is a diocese representative of the candelabrum family (Characeae). It got its German name because of the whitish, star-shaped sprouts arranged like pearls on a string. It is a not very variable species that can only be confused with the shimmering luster alga ( Nitella translucens ).
Occurrence
The star candlestick alga is widespread throughout Europe and North Asia as far as Siberia and Japan. However, this is quite rare in north-western Europe, although it is a bit more common in the northern and eastern parts of Europe. Since it can withstand a low salt content, it is not only found in deep clear water lakes, but also in brackish water on the Baltic and North Sea coasts. Usually it is to be expected at depths between 4 and 10 m in mesotrophic lakes. Recent studies show that not too strong fertilization (anthropogenic eutrophication) does not seem to harm it, as long as the nutrient content does not get out of hand.
Identifying features
The star candelabrum can reach a maximum length of 2 m, but it is usually between 20 and 50 cm long. It is characterized by the missing connection of the rung and the missing spines and stipulars. The star candelabrum forms shoots that are up to 2 mm wide in diameter and usually forms stunted side shoots. Overall, there are only relatively few whorls on the candelabra, with the top whisk usually being relatively small and narrow. The sections between the whorls (internodes) can be up to 20 cm long. The extensive and protruding branches are often swollen spherically at the bottom. They usually form 1 to 3 links, are 5 to 12 cm long and about 1.5 mm wide in diameter. Its end cell is long and pointed. At the base of the plant, the star candelabrum forms characteristic whitish, star-shaped sprouts that are arranged like pearls on a string.
The training of gametangia takes place from early summer to autumn. These are either individually or in a pair next to each other. Often there is no supporting leaf there. The oogon does not have a crown, is 1.1 mm to 1.4 mm high and about 0.9 mm wide, is briefly egg-shaped to top-shaped and has 7 to 9 wide windings. The ends of the spiral cells are swollen and form a lid-like curvature. The dark brown, almost black oospore is about 0.7 mm high and 0.6 mm wide, elongated oval shaped and provided with 7 or 8 thin ribs. The antheridium measures about 1 mm in diameter and is dark greenish to brownish in color.
literature
- Werner Krause, Hanuš Ettl , Georg Gärtner, H. Heynig, D. Mollenhauer: Freshwater flora of Central Europe. Volume 18: Charales (Charophyceae) . - Gustav Fischer Verlag, 1997. ISBN 3-437-25056-6
