Glandular Willow Herb (Epilobium ciliatum)

Photo: (c) Olivier Pichard CC BY-SA 3.0 license

Family: Onagraceae

Growth Habit: Glandular Willow Herb grows up to 1 m. It is a branched weed that is almost hairless. It has broad bluish green leaves that resembles those of Willow and short leaf stems.  Stem is 15 -120 cm tall, red, erect and almost hairless. Often larger than most Epilobium species.

Epilobium is a widespread and abundant genus of herbs in Tasmania. It includes nine native species and three introduced species. The flowers are usually quite conspicuous, and the tiny seeds with large plumes, derived from the long, pod-like capsule are distinctive.

Threatened Species

Epilobium pallidiflorum (Showy Willowherb, rare) – In Tasmania, Epilobium pallidiflorum occurs in wet places mostly in the north and north-west of the State. Similar in height and look but the upper parts of the stem are erect with a dense covering of short hairs that are pressed close together. The fruit capsule is between 5-6 sm.

Epilobium willisii (Carpet Willowherb, rare) – Not in the Tamar. In Tasmania, Epilobium willisii occurs in wet montane herbfields around the central mountains and bare places around the eastern mountains.

Type of Plant: A perennial erect herb.

Photo cropped: (c) Eigenes Werk CC0 1.0 license

Flowers: White or purplish-pink, four petalled flowers are present.

Fruit/Seed: Seed pods are long, more than 6 cm,  and cylindrical.

Dispersal: Willow Herb disperses by seed.

Distribution: Glandular Willow Herb is a very common weed of orchards, gardens and roadsides and bare areas. Prefers relatively wet areas.

Status: Undeclared in Tasmania

Weed Impact:

  • Glandular Willow Herb can have a significant impact in orchards.
  • Glandular Willow Herb is resistant to glyphosate, therefore any area regularly sprayed with glyphosate for weed control may develop an abundance of the weed.

For further information contact the Department of Primary Industry, Parks, Water and Environment, Tasmania.

Control Methods:

  • Mechanical. Cultivation and hand hoeing are effective. Mowing can help control the spread but needs to be done when the plant is not seeding. If seeded plants are mowed this will promote weed spread. Mulching greatly reduces seed germination.
  • Herbicides. Spot spray. Herbicides registered in Tasmania include dichlobenil (and glyphosate but the weed is resistant to glyphosate).

N.B. Always check the herbicide label before use.