Rorippa sylvestris

Wild yellow-cress ( Rorippa sylvestris)

The Wild cress ( Rorippa sylvestris) is in Central Europe most widely occurring member of the cabbage family ( Brassicaceae). It flowers mainly from June to October.

Appearance

The perennial herbaceous plant reaches a height of about 20 to 60 cm. It is a wintering with rosettes kind that drives underground, branched, thin protuberances. The stem grows erect to ascending, branched, glabrous or sparse with very short hair. The leaves are petiolate and not amplexicaul. The lower ones are pinnate to pinnately lobed and have 4-7 pair of serrated to fiederteilige sections on each side. The upper are also sitting and often narrower and undivided sections. The sepals are about 2 to 3 mm long, elliptic to oblong shaped. The petals are 4-5 mm long, designed golden yellow and obovate. The flower clusters are rarely over 10 cm long. The pods are linear, straight or slightly curved, about 8 to 18 mm long, about 1 mm wide and sit on horizontal or slightly sticking up to 12 mm long stems.

Occurrence

Habitat requirements

The Wild cress grows on flood grass and weeds in rubble companies. They usually prefers moist, nutrient-rich, nitrogen-containing humic soils. They are found mainly on the banks, in ditches, in fields and in forest nurseries.

After Ellenberg it is a Verbandscharakterart the Riverside reedbeds ( Phalaridion arundinaceae ).

Popularization

Rorippa sylvestris comes in Europe to North Africa, and West Asia. She is a Eurasian- sub-oceanic sub-Mediterranean Florenelement. In Austria it is often found, while only partially present in Switzerland.

Distribution in Germany

The Wild cress is mostly used in Germany occurring. Only in West and East Germany, it is rare to find.

Ecology

The Wild cress is a Hemikryptophyt: A perennial, overwintering by basal leaves, erect or, depositing stem plant that approximately 20 (-40 ) cm high. Their roots bring forth leafy shoots. The leaves are pinnate to pinnately lobed.

The flowers are " Small funnel flowers ", whose golden-yellow petals are tower over the chalice. The crown base per 2 nectaries are inserted between each two stamens, the scars and the anthers of the four longer stamens are at the same height so that visitors with the head touching both, self-and cross-pollination occurs. In rainy weather the corolla opens only half, and it is by the longer stamens spontaneous self-pollination instead.

Pollination is by insects, such as bumblebees, bees and hoverflies.

The fruits are little pods or pods, 7-8 mm long and pointed. There is water spread of seeds and fruits, as well as people spread through nurseries.

In addition, vegetative propagation as turf -forming Kriechpionier and by root sprouts and by leaf buds. Whole plants can be propagated by flooding.

Others

With up to 0.75 m deep roots and as Kriechpionier the plant can be used for bank stabilization. The roots contain the mustard oil hirsutine.