Giant Hogweed: Biology, Impacts and Management

Edited by Corin Pratt and Marion Seier.

backlit-dawn-dusk-158904
Giant hogweed is a leading invasive plant across Europe and North America, causing numerous ecological impacts as well as severe phototoxic reactions when coming into contact with skin (© Pexels)

Giant hogweed (Heracleum mantegazzianum) is a monocarpic perennial herb, native to the Caucasus region. Since the late 1800s, giant hogweed has spread extensively across Europe and in eastern and western parts of North America following its likely initial introduction to the continent as an ornamental curiosity as early as 1917. Hogweed is an extremely successful invader in part due to its prolific seed production and growth rate. These attributes coupled with its large size allow giant hogweed to significantly alter natural environments and plant community structures. In addition, the plant is hazardous to humans and leaves riparian banks susceptible to erosion as it dies off in autumn.

Continue reading

Himalayan Balsam: Cause or Associate of Soil Erosion?

Himalayan Balsam
Himalayan balsam was introduced as an ornamental plant and has now become a widespread invasive plant (© Stacey Newman)

Himalayan balsam (Impatiens glandulifera) is a non-native annual plant that was introduced into parts of Europe during the mid-nineteenth century as an ornamental plant for parks and gardens.

This plant species was first recognised as an invasive species and a threat to ecological stability in the 1930’s. However, since then the problem has escalated and is now of international concern, due to its negative impact on ecosystem biodiversity. This is primarily due to its ability to out-compete and overcrowd native vegetation. Himalayan balsam has now naturalised in many countries, resulting in a shift in management strategies from attempting to remove the invasive plant, to limiting its territory and further spread.

Continue reading

Parthenium: Controlling the World’s Most Destructive Toxic Weed

IMG_5808
Parthenium is toxic to animals and humans when consumed in high enough quantities (© CABI)

The poisonous Parthenium hysterophorus plant is one of the world’s most destructive invasive plant species, threatening biodiversity, food security and human health across numerous countries. The herb is native to Central and South America but has spread to over 40 countries over recent decades including Australia, India, Ethiopia, Swaziland and South Africa.

Continue reading