Hairy willow-herb

Epilobium hirsutum

Keys to Identification

  • Flowers are pink with a white, split stigma

Family

Onagraceae – Evening Primrose family

Other Names

Codlins and cream

USDA Code

EPHI

Legal Status

Colorado Noxious Weed List A

Identification

Lifecycle

Perennial

Growth Form

Forb

Flower

Flowers are deep pink, single, ½-1 inch wide, 4-petaled, with a white style.  Stigma split into 4 segments

Flowers June-August

Seeds/Fruit

Seeds with a white silky tuft in a long seedpod, viable for up to 5 years

Leaves

Leaves opposite, ½ inch wide and 2-4 inches long, lance-shaped with toothed edges, attached directly to stem

Stems

Plants are 3-6 feet tall.  Stems covered in soft hairs

Roots

Fibrous roots, rhizomes and stolons

 

Impacts

Agricultural

Creates monocultures that can clog waterways

Ecological

Very invasive, colony forming.  Can crowd out cattails and Purple loosestrife

 

Habitat and Distribution

General Requirements

Found in wetlands and meadows

Distribution

Found in riparian and wetland areas at lower elevations

Historical

Native to Europe

Biology/Ecology

Mode of Reproduction

Reproduces by seed, rhizomes and stolons

Dispersal

Wind, animals and human.