NATIVE RANGE: East Asia

FIRST FINDING IN SLOVENIA: 1950

PATHWAYS: ornamental plant

POSSIBLE TO FIND: year-round

FLOWERING SEASON: July-September

DESCRIPTION: Dioecious annual or, in optimal conditions, perennial climbing plant, which may vigorously grow over other plants. It is a left-handed twining plant (climbing anti-clockwise). Leaves are about as broad as long, palmately divided into 5 to 9 elliptic lobes. Stems, leaves and stipules are covered with stiff hairs. These are most pronounced on the undersides of leaves. Green flowers are borne in upright spikes. The fruiting head is a pendulous cone-like structure, up to 4 cm long, initially green and brown when ripe.

HABITAT: Riparian forests, forest edges, roadsides and ruderal habitats.

STATUS: Occurs locally, especially in parts of Hungary and in Northern Italy. Known from a few localities in Central and Eastern Slovenia. Grown as an ornamental plant in gardens. 

SIMILAR SPECIES: Common hop (Humulus lupulus) is a dioecious, perennial, right-handed twinning plant (climbing clockwise). Leaves palmately compound with 3 to 5 lobes which have a cordate base. The leaf stalk is shorter than the lamina. Virginia creeper (Parthenocissus quinquefolia) is also a climbing plant with palmately compound leaves, but has 5 to 7 stalked leaflets. Its fruits are dark blue berries.

SOURCE: Field Guide to Invasive Alien Species in European Forests