American skunk cabbage

Lysichiton americanus

Origin: Western North America

Route of introduction: Ornamental plant trade

skunk cabbage id features

A robust herbaceous perennial with produces a large unpleasant smelling bright yellow flower in early spring followed by rich green oval shaped leaves.

Leaves: large, shiny and leathery growing in a cluster at the base of the plant. Each leaf is bright green and can measure up to 70cm long

Flowers: flower borne on a long, fleshy inflorescence which is surrounded by a bright yellow structure known as a ‘spathe’. Flower in late spring March-May that resemble those of a wild arum (lords and ladies). Flowers emit a strong foul smell like that of a skunk hence the name. In general only flower and fruit at around 2 to 3 years old and individual plants may not flower every year.

Seeds: after flowering around 150-350 green berries form on each spadix. Each berry typically contains 2 brown seeds which are up to 1 cm.

Impacts:

Biodiversity: when it becomes invasive skunk cabbage can form dense stands shading out native vegetation. Skunk cabbage grows well in wet woodland and pond/stream edges and can prevent the regeneration of native species by shading.

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Control:

Mechanical: digging out is possible but must be thorough as roots systems can be extensive.

Chemical: glyphosate based chemical applied to leaf coverage is effective in summer, adjuvant necessary due to waxy cover and shape of leaves.