Persicaria amphibia

Water knotweed ( Persicaria amphibia )

Water knotweed ( Persicaria amphibia ) is a plant from the family of the buckwheat family. Depending on site conditions (water level ), it forms from water and land forms.

Occurrence

The plant grows mainly in stagnant water, on the banks, on wet meadows and fields. It is circumpolar spread.

Description of the plant

The water knotweed is a perennial herbaceous plant. The landform is about 30 to 100 cm tall; the water can form 60 cm to 3 m ( rhizome ) are long and very long -stalked, oblong- elliptic, up to 10 cm long leaves. The lamina of the leaves has a lawned to heart-shaped base. In contrast to the barren floating leaves, the leaves of the landform have a flat coat. They grow to 20 cm long and are short-stalked. Some of them have a dark mottling.

The often unisexual flowers are pink colored and have no glands. They usually forms from five stamens. In addition, the individual flowers are in pseudo-spikes and the individual flowers often overlap.

Ecology

As an amphibious plant the water knotweed can with sufficient basic moisture both on land, eg occur on dry roadsides, and in the water.

The landform is a sticky hairy, narrow- stem plant with pithy stems, blooms rarely. The landform is a Hemikryptophyt and has adjacent hairy leaves. On dry sites, the seed set remains off, but there is a intense, emanating from the rhizome multiplication.

The water form is Schlammwurzler with broad floating leaves and top-side stomata, the stems have in this case wide air corridors and up to 3 m long, arching, ascending swimming rung. In addition, the water form has a higher proportion of antibiotic substances on the landform. The water is a form hydrophyte which is anchored with a rhizome in the bottom of the water and having elongate, bare floating leaves.

Is pollinated by insects, the water knotweed. Often self-pollination occurs. The spread of the seeds via the water ( Hydrochorie ).

System

The name was introduced by A. Delarbre. For some time now Polygonum is reused, which is also eponymous, was for the family of the buckwheat family, Polygonaceae the. It was first described by Carl Linnaeus. Both names are used interchangeably, however. Amphibium is often used instead of amphibia.