Stratiotes aloides
Crab Claw ( Stratiotes aloides )
The Crab Claw ( Stratiotes aloides; old: Str potamios, St. aquatica, Militaris aizoides, aquatile Sedum, Aloe palustris ) is a Wasserpflanzenart from the family frog bite plants ( Hydrocharitaceae ). It is the only extant representative of the genus Stratiotes that still included other types then occurring in Central Europe during the Tertiary.
Features
The plant produces up to 40 centimeters wide, rosettes arranged leaves, which partly emerging from the water in the growing season. The funnel-shaped growth form is reminiscent of an aloe, the leaves are cut wide, triangular and hooked forward facing up to four centimeters. The bracts of their stems look similar to the scissors of cancers. Through intensive formation of foothills in the leaf axils, the individual rosettes are submerged joined together to form larger units. Down drives the plant dense clumps of long, unbranched water roots to absorb nutrients from the open water. The flowers can reach a diameter of three to four centimeters and consist of three white crown and three green sepals; the center with the reproductive organs is yellow. The species is dioecious; So there are male and female plants. The flowering period extends from May to July. The egg-shaped, hexagonal fruit is up to 3.5 inches long. More important than the spread by seed but vegetative propagation by offshoots. In late autumn the plants sink to the bottom of the water to rise again until the spring.
Occurrence and risk
Crab claws grow warm, sheltered, muddy in floating leaf companies, mesotrophic to eutrophic, base -rich, not dirty and mostly still waters of the flood plains, such as oxbow lakes, ditches, ponds and canals. The type is (except the southern / Mediterranean) Eurasian- continental spread of Europe to western Siberia. In the north German lowlands scattered before it comes, with accumulations in the floodplain of the lower reaches of rivers. Such a distribution area, for example, the Bremen / Weser march. In the hilly and mountainous country, the crab claw is rare and missing over long distances. She is on the red list of endangered species and is " specially protected " within the meaning of the Act ( BArtSchV, Federal Species Protection Ordinance ). The plant is sensitive to strong fluctuations of the water level and to contamination. Your stocks are decimated by measures Watercourse management ( grave clearance, aquaculture ). Some anglers remove illegally disturbing for them floating carpets.
Special
The plants that like to grow at very sociable occurrence, drive only during the summer season at the water surface. In autumn, the rosettes sink to the river bottom and form winter buds ( turion ); the outer leaves die off. This coming spring, the winter buds rise to the surface and form new plants. But the heart of old roses floats after overwintering on the ground up again and continues to grow. The strong biomass production of large deposits acts promoting siltation ( forming sludge ) in the aquatic environment. By flooding the species is common. Where it often happened, she was formerly used as pig feed and because of its high phosphorus and potassium content of green manure.
The Großlibellenart Green Darner has become quite specialized in their oviposition on the crab claw and is therefore bound by their occurrence.
In 1998, the crab claw was chosen as the flower of the year. She is also a popular ornamental plant for ponds.
Name
Further, some rare German names are: Agel, water blessing or saw, purse, water sickle, sickle herb or saber herb ( after the pointed shape of the leaves ), water Scheer or scissors, Krabbenklau, ( such as cancer scissors probably because of the " scissor-like shells of the inflorescences " ), Pickerel weed ( the name of several aquatic plants, between which like to stay pike ), water, marsh or Afteraloe ( external resemblance to some species of Aloe, just hence the species name aloides ), Reiter herb ( perhaps to Greek στρατιώτης ( stratiotes ), soldier, warrior ' ajar ); completely taken over by other plants are the designations water spring (otherwise Hottonia palustris ) and water fennel ( Oenanthe otherwise, and for the treated plant here also Wrong or thunder Beard water fennel ). The name Stratiotes ( potamios ) itself is transferred from one occurring on the Nile plant ( Pistia stratiotes well ) that describe Pliny the Elder and the military physician Dioscorides as a wound healing agent.