Home > Alien species in Slovenia > Alien plants > Giant hogweed
NATIVE RANGE: West Asia (Caucasus)
FIRST FINDING IN SLOVENIA: 1980
PATHWAYS: ornamental plant; seeds secondary spread by water and with transported soil
POSSIBLE TO FIND: April – November
FLOWERING SEASON: June – September
DESCRIPTION: A very large monocarpic herbaceous plant. Leaves are 1−1.7 m broad, twice pinnately divided and deeply incised. Leaf margin dentate with sharp white-tipped teeth. Stems are green with many scarlet spots and are covered with stiff hairs. Numerous white to greenish-white flowers are borne in large umbrella-shaped clusters. Dispersal is exclusively by seeds, which can be transported by water. People also unintentionally spread seeds by transporting soil. The whole plant is toxic to touch!
HABITAT: Forest margins, riparian areas and ruderal sites.
STATUS: Widespread and common in western and parts of Central Europe. Only few observations in the Mediterranean countries. In Slovenia found in isolated localities throughout the country, but mostly in Ljubljana and surroundings. In most locations control and eradication actions are carried out.
SIMILAR SPECIES: European cow parsnip (H. sphondyllium) grows to a maximum of 2 m height, has serrated leaf margins with rounded teeth and a green to reddish, unspotted stem. Wild angelica (Angelica sylvestris) and giant hog fennel (Peucedanum verticillare) have entirely reddish stems and leaves with a different shape. The alien Persian hogweed (H. persicum) and Sosnowsky’s hogweed (H. sosnowskyi) are both very similar.
SOURCE: Field Guide to Invasive Alien Species in European Forests
NOTE: this species is included in the list of Invasive Alien Species of Union concern (the Union list) of Regulation (EU) 1143/2014. The species included on the Union list are subject to restrictions and measures set out in the Regulation. These include restrictions on keeping, importing, selling, breeding and growing. Member States are required to take action on pathways of unintentional introduction, to take measures for the early detection and rapid eradication of these species, and to manage species that are already widely spread in their territory.