Subularia aquatica
Illustration of Subularia aquatica
Subularia aquatica is a flowering plant in the family of the cruciferous plants (Brassicaceae ). This unusual species occurs in littoral and aquatic habitats. As a German common names are " Pfriemenkresse " or " water - Pfriemenkresse " led.
Description
Subularia aquatica grows as annual herbaceous plant, reaching heights of growth between 1.5 to 15 (rarely 0.5 to 23 ) centimeters. It is a short, thickened, underground stem axis exists with fibrous roots. There are only basal, erect or ascending leaves with pfriemlichen and ganzrandigen leaf blades available that are 1 to 7 (rarely 0.5 to 10 ) inches long.
In racemose inflorescences usually stand together two to twelve (one to 18 ) flowers. The flower stems are up to fruit ripening 1-7 (rarely to 10 ) mm long. The flowers are only open when growing on the water surface and cross-pollinated flowers. Are they constantly under water, they remain closed and pollinate itself The sepals have a length of usually 0.7 to 1 ( 0.5 to 1.3 ) mm and a width of 0.2 to 0.5 (rarely to 0.7 ) in mm, the small white petals have a length of 1.2 to 1.5 mm and a width of 0.2 to 0.5 millimeters.
The little pods are usually 0.2 to 0.35 ( is 0.15 to 0.55 ) mm × 1.2 to 2 (rarely to 2.5 ) inches tall. The from 0.8 to 1 mm × 0.5 to 0.8 millimeters large seeds are light brown in color.
The flowering period extends from July to October.
The chromosome number is 2n = 28, 30 or 36
System
Subularia aquatica L. belongs to the genus in the tribe Subularia Cardamineae in the family Brassicaceae.
The type Subularia aquatica contains two subspecies:
- Subularia aquatica L. subsp. aquatica: the fruit stalks are starting at an angle of 50 to 90 degrees from the axis of grapes. The sepals fall off early. The little pods are ellipsoidal. It represents the kind in Europe and Asia.
- Subularia aquatica subsp. americana GAMulligan & Calder: the fruit stalks are at an angle of 30 ° to 50 ° from the axis grapes. The sepals remain until fruit maturity. The little pods are broadly ellipsoid to broadly ovate. She represents this kind in North America.
Occurrence
The occurrence focus in Europe is located in Scandinavia, Scotland and Iceland, island-like deposits rich south to the mountains of the Iberian Peninsula and the Balkan Peninsula. Furthermore Subularia aquatica comes to close to the sea areas of the boreal and arctic North America before and on the Kamchatka Peninsula.
One type of beach Ling corridors flat, sometimes up to 50 cm deep flooded lakeshore. It prefers acidic, humus-rich, oligotrophic (up to dystrophic ), rather schlammge sandy soil.
Morphologically similar species
Can be confused aquatica Subularia with many other small tufted, aquatic plants, such as species of the genus of bulrushes ( Eleocharis ), the water lobelia (Lobelia dortmanna ), the lake quillwort ( Isoetes lacustris ), Limosella acaulis, Lilaeopsis occidentalis or Lilaea scilloides.
Importance and use
Subularia aquatica offers itself as a habitat for small animals and stabilizes the shore areas. This species is occasionally cultivated as vegetation for aquariums.
Threats and conservation measures
Subularia aquatica is listed in the Red List of Germany and some of its provinces as " extinct or lost ." In Switzerland, the species is extinct in the category " RE " for regionally Extinct, so in Switzerland, ranked. In the U.S., the species is provided by the states of Maine, Michigan, Minnesota and New York with hazard categories.