Lychnis viscaria 'splendens'
It is an upright perennial, growing to 60 cm in height. It gets its name from the stickiness of its stem. It has a purple flower. Lychnis viscaria is said to increase the disease resistance of surrounding plants. Extract from L. viscaria contains a relatively high amount of brassinosteroids, which have a proven positive effect on the growth of other plants. In Germany the extract is allowed for use as a "plant strengthening substance."
It grows on cliffs and in rocky places.