NATIVE RANGE: East Asia (China, Korea, Japan)
FIRST FINDING IN SLOVENIA: 2017
PATHWAYS: horticulture, experimental use for prevention of erosion
POSSIBLE TO FIND: year-round
FLOWERING SEASON: July-September
DESCRIPTION: A fast-growing climbing vine, which can grow up to 30 cm per day. It can climb over trees and other vertical structures but in the absence of these, it trails over the ground. Leaves are palmately compound with three leaflets, of which the terminal leaflet is three-lobed, while the side leaflets are two or three-lobed. Leaflets have pillose undersides and edges. Purple to red flowers are borne in upright clusters, up to 15 cm long, and have a yellow spot at the base of upper petals. The fruit is an up to 8 cm, densely pillose pod. It has a strong, perennial taproot and mainly reproduces vegetatively via stolons (runners) which root at the nodes.
HABITAT: Montane forests, forest edges, ruderal habitats.
STATUS: Found locally in Switzerland, Italy, Slovenia, Croatia, Bosnia and Herzegovina, Ukraine and Russia. In Slovenia, first found in 2017 and 2018 in two locations in the Primorska region.
SIMILAR SPECIES: Common bean (Phaseolus vulgaris) has a similar growth habit, but its leaflets are not palmately compound and have only a few hairs. Its red, pink or white flowers are borne in loose clusters and don’t have a yellow patch in the centre.
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.