American skunk cabbage - Lysichiton americanus

Native Range and Distribution:
Native to Western North America (Rotteveel, 2009), the American skunk cabbage plant (fig. 1) was an important resource to Native Americans. Its large and waxy leaves were used as dressings for wounds, while the whole plant could be consumed when other food was scarce (NBN Atlas, 2024). 
In 1901, American skunk cabbage was first planted in the UK, being used as an ornamental plant. In 1947, it was identified in the wild for the first time (UK Government, 2019). Figure 2 demonstrates the modern distribution of American skunk cabbage across the UK. In Scotland, the species appears most common around the central belt, while in the East Grampian area it appears most prevalent around the River Don. 
 

Habitat and Physical Characteristics: 
American skunk cabbage prefers wetter environments, so it is found near to streams, bogs, and ponds (SISI, n.d.). It can be identified by its striking yellow flowers, leathery texture, and unpleasant skunk-like smell (Brown, Booy and Hill, n.d.). Its seeds may be transported via rivers, allowing the species to further colonise riverbanks. 
Aside from requiring water, the species can thrive in a wide variety of conditions, from bright light to shade (SISI, n.d.) and acid to alkaline soils (Brown, Booy and Hill, n.d.). 

Impacts:
Being so adaptable, the species is a risk to most wetland terrestrial (and some coastal) environments. Their large thick leaves block the sun from other species, resulting in displacement and local extinctions. Most often the species affected are mosses and vascular plants (Rotteveel, 2009). 

Management: 
Until 2016, the species was commercially available to buy in the UK. However, EU invasive species regulation now determines that the intentional keeping of American skunk cabbage is illegal (European Commission, 2022). Post Brexit, the UK maintains the use of this European law. 
Removal of existing populations is often achieved using herbicides, however using herbicides near to bodies of water can pose enviornmental risks. The plant may also be pulled up from the root, although as they grow with large root systems, it can be difficult to effectively remove the whole plant. (SISI, n.d.).