Oriental bittersweet

Celastrus orbiculatus

Overview

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. 
For further queries, you can contact the Non Native Invasive Species team in the Northern Ireland Environment Agency on 028 9056 9558 or Email: invasivespecies@daera-ni.gov.uk                                                                                                     
Invasive Species Northern Ireland

Invasive Species Northern Ireland