Hairy Willow-herb

Hairy Willow-herb
Hairy Willow-herb. Epilobium hirsutum.
Onagraceae, the evening-primrose family.

Plant: Robust, erect, often branching, very hairy plants, to 5', with bright pink flowers on elongating seed pods growing in a leafy cluster mostly near the ends of branches. Perennial.
Flowers: Bright pink, about 1" across, with four deeply notched petals, on top of a long seed pod. Stigma divides into four parts, forming a cross characteristic of many members of the family. Flowers arise from axils mainly in leafy clusters at the top of the plant and ends of branches.
Leaves: Mainly opposite, simple, narrowly ovate, to lanceolate, 1"-4", sharply toothed, sessile, and hairy on both sides.
Fruit: Long, narrow capsule, 2"-3", with square cross-section, growing rapidly while the flower is still blooming on the tip, and persisting for some time before splitting in four parts to release seeds attached to silky hairs.
Blooming: July-September.
Habitat: Waste places, meadows, often in damp areas.

Comments: Plant and flowers much larger than several other willow-herbs in our area (e.g. American Willow-herb E. ciliatum). The plant is somewhat similar in appearance to Fireweed Chamerion (previously Epilobium) angustifolium, but differs in having deeply notched petals and being altogether much hairier. The species is naturalized from Europe.

Where to find it: Uncommon in the park. I have found it at one spot on the south shore of the pond, and on the north shore of the parking lot drainage pool.