Celastrus orbiculatus Thunb.
Family: Celastraceae
Asian Bittersweet,  more...
Celastrus orbiculatus image

Perennial woody vine 6 - 20 m long

Stem: green to light brown, climbing by winding around a support (twining).

Leaves: alternate, stalked, 5 - 10 cm long, about as wide as long, circular to oblong or inversely egg-shaped with a rounded to wedge-shaped base and a pointed to blunt tip, round-toothed. Leaves turn yellow in fall.

Flowers: male, female or bisexual, borne in clusters in leaf axils, greenish, five-petaled.

Fruit: a three-lobed capsule, in hanging clusters in leaf axils, orangish yellow to orange, about 6 mm wide, spherical, leathery, splitting into three parts, each part containing one or two persistent seeds with a red covering (aril).

Bark: brown, smooth, peeling in thin layers with age.

Similar species: Celastrus scandens has larger fruit clusters that form at the ends of branches, and its leaves are usually twice as long as wide.

Flowering: late May to early June

Habitat and ecology: This aggressive weed was introduced from Asia in 1870 and has escaped from cultivation. It has invaded the dune region of Indiana including pannes, young shrub and small tree communities, and young maple forests. It often strangles Pinus baksiana (jack pine), which is rare in Indiana and endangered in Illinois. It climbs a native species and smothers it by shading the leaves and competing for water, nutrients and space. It also constricts trunks and stems, inhibiting sap flow. The weight of the vine can make a plant top-heavy, leading to breakage in strong winds. Across the eastern United States, C. orbiculata threatens native vegetation in thickets, open woods, and along roadsides.

Occurence in the Chicago region: non-native

Notes: This species should not be planted in the landscape. It is very aggressive and escapes into natural areas, competing with the local vegetation. The fruit is not as ornamental as that of the native C. scandens. Both C. scandens and C. orbiculata have poisonous fruit.

Etymology: Celastrus comes from the Greek name for an evergreen tree, kelastrus. Orbiculata comes from the Latin words meaning "round and flat," referring to the leaves.

Author: The Morton Arboretum

Much like no. 1 [Celastrus scandens L.]; lvs suborbicular to broadly oblong- obovate; fls few in small axillary cymes much shorter than the subtending lvs; 2n=46. Native of e. Asia, established as an escape in open woods and thickets here and there from Conn. s.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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