Potamogeton crispus

Krause's pondweed ( Potamogeton crispus )

The multi-annual, winter or summer green Krause pondweed ( Potamogeton crispus ) is a plant species of the family of the pondweed family ( Potamogetonaceae ).

Description

The Krause pondweed is a submerged aquatic plant and can 30 cm to 2 m long. The plant forms underground runners, the square stems is often compressed laterally. It forms elongated submerged leaves that are curled at the edge and distinctly toothed. (see illustration) The stipules are from leaf base free.

The inflorescence is terminal on the shoots and rises on a short stalk above the water surface. The inflorescence is a loose, 1 to 1.5 cm long cylindrical spike. The fruits are grown together at the base and provided with a long, greenish, beak-like outgrowth. In the fall Turionen arise ( winter buds ) directly on the foliage drive. The Krause pondweed can also develop special Überdauerungsformen that sink to the river bottom in winter and at the same time represent a vegetative propagation ability.

Occurrence

The water plant is usually (often heavily contaminated or dirty ) from May to September meso-to hypertrophic standing or slow-flowing waters to be found. It is often spread across Germany and many parts of Europe and Asia up to the mountains. In America, it occurs as a neophyte.

Ecology

The flower spikes protrude vertically out of the water. For the flowers carried wind pollination; About water pollination (when the unwettable pollen is carried by water to the scar ) or animal pollination ( by water striders, water spiders, water snails). The flowers are hermaphroditic and vorweiblich, they have taken the lack of perianth 4 perigonartige stamen appendages that temporarily record the outgoing pollen. Bloom time is from June to August.

The fruits are small drupe -like nuts with a curved beak hooked at the tip. There is swimming propagation and random and Velcro spread by waterfowl. Random dispersal by fishes is likely; in any case it has been demonstrated in Potamogeton natans. Fruit ripening is from September to October.

Asexual reproduction occurs through the easy -terminating stem elements ( corresponding to a self, Velcro and swimming propagation ), as well as turion that germinate in late summer and winter green.