Luronium
Frog Orchid ( Luronium natans )
The frog orchid ( Luronium natans ), also called Floating Frog herb, is the only species of monotypic genus Luronium within the family of plantain plants ( Alismataceae ). In Central Europe the frog herb has become rare and is under strict protection. The specific epithet natans comes from the preferred growing sites on the shore zones of water - in habitats of frogs.
- 5.1 Literature
- 5.2 External links
Description
Vegetative characteristics
The frog herb grows as a perennial herbaceous plant. The leafy stems are 10 to about 40 inches long. This aquatic plant grows either flutend under water or - for temporary dehydration or water level fluctuation of the water - even crawling on the ground. At the nodes roots are formed. The leaves are elongated linear underwater while oval, 3-6 cm long, pedunculated floating leaves are formed on the water surface.
Generative features
The axillary flowers that rise above the water surface between May and August, have the typical plantain plants three white, rounded petals on (see: Common plantain, Common Arrowhead, but also frog bite plants like frog bite and crab claw ), the one to one and a half centimeters in diameter reach. The flower base is yellow colored and with six stamens and six to nine: equipped carpels (rarely twelve). The carpels are 12 - to 15 - acuminate Rippig and also the stylus. The green sepals are only a third as long as the petals.
Ecology
The vegetative propagation or spread via runners, winter buds and seeds. The latter can take a long time in the diaspore reservoir of the soil so that the plant can appear suddenly after years of absence again when set about by care measures in a biotope suitable site conditions ( see for example: black water).
Occurrence
Frog herb is an atlantic to subatlantisch widespread in Europe only plant species. In detail, including France, Britain, the Netherlands, Germany, South Sweden and parts of Poland are populated. In Germany, most representatives of the northwestern lowlands, and especially in Western Lower Saxony is - especially in the Emsland region and in East Friesland. In the South Heath, in Munsterland, on the Lower Rhine and the southern Holstein and in a climate rudimentary " atlantic colored " part area south of Brandenburg and Saxony Northeast there is selective evidence. In central Germany, Austria and Switzerland, however, the type does not occur.
These plant communities to a characteristic species of the class Littorelletea ( beach Ling corridors ), also in the order Potamogetonion ( pondweed companies) occurs. Frog herb preference is gappy pioneer stocks flat flooded, alternately wet Ufersäume at most moderately nutrient -rich ( mesotrophic ), basen-/kalkarmer Still waters which are slightly to moderately acidic and have a rich, sandy mud bottom (see also: Heideweiher ).
Hazard protection
Frog herb is a strong decline in located, low competitive nature, which is affected by the general eutrophication of the countryside and of many waters by agriculture as well as intensive fish pond management. Due to the unnatural nutrient inputs are stärkerwüchsige water and marsh plants promoted that displace the frog herb.
On the red list of threatened plant species in Germany Frog herb is classified as " critically endangered ", as well as on the appropriate Red List of Lower Saxony. In North Rhine -Westphalia, where the species occurs only in the north-western sandy areas, it is considered " critically endangered ", and the same is true of Saxony.
In the Fauna-Flora -Habitat Directive of the European Union, the plant is performed among others in Appendix II, which means that for existing deposits specially protected areas need to be established. According to the Federal Nature Conservation Act it is " strictly protected ".