[3] This perennial herbaceous plant usually occurs in wetlands, but may be found in a great variety of habitats, including disturbed areas and roadsides, at elevations below 1,400 metres (4,600 ft).

The fruit is a narrow, hairy, four-chambered capsule up to 10 centimeters in length which may be held on a long stalk.

Epilobium ciliatum is native to the southern part of Canada and most of the United States of America.

It arrived in northern Europe early in the 20th century and spread rapidly, reaching Finland in about 1920.

It is a plant of moist places, stream-sides, ditches, ponds, gardens, roadsides, recently cleared areas and wasteland.