Oriental bittersweet

Habitat

• Found natively on lowland slopes, in thickets, as a hedge plant and under the canopy of low-light forests 
• In introduced areas it is found growing on roadsides, fence-rows, hedgerows, saltmarshes, coastal areas and the edges of fields and forests
• Utilises trees, shrubs and scaffolding to climb upwards

Description

• A deciduous, woody, twining vine, which sometimes occurs as a trailing shrub
• Stems are brown in colour, and older stems can reach 10cm in diameter
• Glossy, rounded, finely toothed leaves are arranged alternately along the stem
• Leaves vary in size from 2-12cm long
• Small greenish-yellow flowers grow from the leaf axils, with 5 petals and 5 sepals
• Fruits are 1cm wide, globular and green in colour, turning bright yellow as they mature
• Fruits split when mature to reveal a red aril (seed covering)
• The outer surface of the plant roots is bright orange

Origin and Worldwide Distribution

• Native to China, Japan, Korea, Mongolia and Russia
• It is now widely spread across North America and New Zealand
• It has been introduced in localized areas across Europe, including one occurrence in England

Potential or Known Impacts

• Suppression and exclusion of native species as result of competition
• They choke and shade the plants they climb on, sometimes killing them
• They can weaken the roots of host trees, leading to collapse

Is it found in Northern Ireland?

• It is not currently present in Northern Ireland

How could it get here?

• Introduction would likely be a result of the accidental or deliberate spread of individuals grown in gardens as ornamental vines
• Dumped seeds and pieces of root moved in soil e.g. to landfill can also cause spread
• Once present, spread can continue by dispersal of fruits via birds and other wildlife

Management/Methods for Prevention

• Prevention via enforcing the IAS (Enforcement and Permitting) Order (Northern Ireland) ensuring that C. orbiculatus is not introduced to Northern Ireland
• Reporting all sightings so that Rapid Response can be instigated
• If Rapid Response is not successful, management can include physical and chemical control

Current Legislative Position (Entry into force: 02 August 2027)

• This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment.