Invasive climbing plants in the Bay of Plenty (New Zealand)
Many invasive alien plants in the Bay of Plenty (North of New Zealand) are climbing plants. These species are very destructive to native plants and the regeneration of native forests because of their smothering effects. They were almost all introduced for ornamental purposes, and usually naturalized during the second half of the 20th century.
Each species has been checked against the Global Compendium of Weeds (GCW) in order to indicate its invasive behaviour elsewhere in the world, as well as in the DAISIE and EPPO databases for its occurrence within the EPPO region. This later information remains only indicative.
Some of these climbing species, which are invasive in the Bay of Plenty, are already established in the EPPO region:
Asparagus asparagoides (Asparagaceae) originates from South Africa. It is a slightly woody winter perennial vine, growing up to 3 m tall. The flowers are small, greenish-white; the berries are small, red and sticky. The plant is spread by birds, eating the berries and distributing the seeds in their droppings. It is also spread by human either deliberately by planting it or by dumping garden refuses on roadsides, waste ground or forest margins.
A. asparagoides is considered W, SW, N, AW, EW by the GCW*. Within the EPPO region, it is established in France (including Corse), Italy, Malta and Portugal (Azores and Madeira only).
Araujia sericifera (Asclepiadaceae, EPPO Alert List) originates from South America. It is a woody, climbing, evergreen vine reaching up to 10 m length and containing irritating and smelly sap.
A. sericifera is considered W, SW, NW, AW, EW by the GCW*. Within the EPPO region, it is established in France (including Corse), Greece, Israel, Italy, Portugal (Azores and Madeira only) and Spain.
Ipomoea indica (Convolvulaceae) originates from the tropical Pacific region and the Americas. I. indica is a high climbing perennial with running stems. Leaves are heart–shaped and usually three-lobed. The flowers are up to 10 cm wide and are intense purple or blue in colour. I. indica regenerates vigorously from fragments when dumped in waste areas. It has occasionally been found to produce viable seeds.
I. indica is considered W, N, AW, EW by the GCW*. In the EPPO region, it is recorded in Cyprus, France (including Corse), Greece, Israel, Italy (including Sardinia), Malta, Portugal (including Azores, Madeira), and Spain (including Baleares, Islas Canarias).
Lonicera japonica (Caprifoliaceae) is native to East Asia. It is a woody vine growing up to 10 m long. Leaves are oval to oblong in shape. Flowers are tube-like and fragrant and white to yellow in colour. Fruits are small and black. The plant occurs primarily in disturbed habitats such as roadsides, shrublands or wastelands. The weight of accumulated vines can topple host trees or shrubs.
L. japonica is considered W, N, SW, AW, EW by the GCW*. The plant is established in France (including Corse), Ireland, Italy, Portugal (including Azores, Madeira), Spain (including Baleares, Islas Canarias), Switzerland, and United Kingdom.
Some other invasive species in the Bay of Plenty have a very limited distribution in the EPPO region, or are absent:
Actinidia spp. (Actinidiaceae) or wild kiwifruit are native of China and Northeast Asia. Actinidia spp. are naturalized plants which have generally established via seed from fruits of the kiwifruit horticultural crop. Wild kiwifruit establishes in forests, in shrub communities or along stream banks in close proximity to kiwifruit orchards or where reject kiwifruit has been fed to stock.
A. chinensis is recorded as the only Actinidia species established in Europe and is only considered W by the GCW*.
Asparagus scandens (Asparagaceae) originates from South Africa. This vine invades forest areas, twining around and strangling host shrubs and trees.
A. scandens is considered W, EW by the GCW*. It is not known to occur in the wild in the EPPO region.
Boussingaultia cordifolia (= Anredera cordifolia) (Basellaceae) originates from South America. It is an evergreen climber growing from a fleshy rhizome. It has bright green, heart-shapped, shiny leaves. Wart-like tubers are produced on aerial stems. It has masses of fragrant, cream flowers. The plant spreads via tubers which detach very easily. It smothers other species and is difficult to control.
B. cordifolia is considered W, SW, N, AW, EW by the GCW*. In the EPPO region, it is established in France (including Corse), Greece, Italy, Portugal (including Azores, Madeira), and casual in mainland Spain (but established in Baleares).
Celastrus orbiculatus (Celastraceae) originates from Japan, Korea and Northern China. It is a deciduous woody climber growing up to 12 m long, with stems 10 cm in diameter. Leaves are alternate, variable in shape, 10-15 cm long. Due to its high reproductive rate, long range dispersal, ability to produce root suckers and rapid growth rate, this plant is a threat to native plant communities and forestry plantations.
C. orbiculatus is considered W, NW, EW by the GCW*. In the EPPO region, it is recorded as established in United Kingdom, and as casual in Belgium and the Czech Republic.
Cobaea scandens (Cobaeaceae) originates from Central and South America. It has purplish stems and light oval green leaves. Large purple lantern-like flowers appear from spring to autumn and are followed by oval fruit 6-10 cm long, which explode during summer to release winged seeds. Seeds spread over short distances by wind, and further by soil or water movement. Although frost tender, it flourishes in the Bay of Plenty.
C. scandens is considered W, EW by the GCW*. It is not known to occur in the wild in the EPPO region.
Jasminum polyanthum (Oleaceae) originates from China. It has small pointed leaves, and starry white flowers. Globular, glossy black fruits are occasionally produced, which are spread by birds. The plant climbs vigorously through other vegetation, forming roots where it touches the ground. Spread is mainly from vine fragments or from dumped garden wastes.
J. polyanthum is considered W, SW, EW by the GCW*. In the EPPO region, it is only recorded as established in Madeira (PT).
Passiflora mollissima and P. mixta (Passifloraceae) are native to tropical South America. They are evergreen climbers that can grow up to 10 m. The dark green leaves are three lobed, and the plants have large, pink, hanging, star-shaped flowers. The fruit is golden yellow when ripe. Inside is a sweet, orange pulp, filled with black seeds which are readily dispersed by rats, possums and birds.
P. mollissima is considered W, N, SW, AW, EW by the GCW*, and P. mixta W and EW. P. mollissima is only recorded in Madeira (PT), P. mixta is not recorded to occur in the wild in the EPPO region.
Rumex sagittatus (Polygonaceae) originates from South Africa. R. sagittatus is a climbing perennial; it has tubers up to 10 cm long and extensive rhizomes. It establishes along road edges and infests coastal areas and waste areas. The leaves are arrowhead shaped. The small, papery, pink-yellow flowers are gathered in clusters and form fruits which are wind-dispersed. Tubers and root fragments spread through water and soil movement, as well as through dumping of garden waste.
R. sagitattus is considered W, AW, EW by the GCW*. It is not known to occur in the wild in the EPPO region.
* Abbreviations for the Global Compendium of Weeds:
W: Weed; SW: Sleeper Weed; N: Noxious Weed; AW: Agricultural Weed; EW: Environmental Weed.
Delivering Alien Invasive Species Inventories for Europe (DAISIE). http://www.europe-aliens.org/
A Global Compendium of Weeds http://www.hear.org/gcw/alpha_select_gcw.htm
Bay of Plenty Regional Council – Plant Pest Control – Climbing Plants. http://www.ebop.govt.nz/land/media/pdf/pp1700.pdf