Submitted to: CABI Crop Protection Compendium
Publication Type: Book / chapter
Publication Acceptance Date: 12/31/2003
Publication Date: 7/1/2004
Citation: Balciunas, J.K. 2004. Delairea odarata lemaire. CABI Crop Protection Compendium, 2004 edition [CD-ROM]. CAB International, Wallingford, United Kingdom. Interpretive Summary: Frequently, plants from overseas become naturalized in the USA, and some cause serious economic losses and environmental damage. While the impacts of many non-indigenous weeds is well know, for others, their spread and impact is only now being evaluated and assessed. One of these is the South African vine, Cape ivy, also known as German ivy. Although still widely sold as a houseplant, this vine is established in several states, but is most widespread and damaging in California. While it establishes most readily along streams and lake shores, from there it readily invades into forests, shrub thickets, and grasslands. Usually, this vine forms a thick carpet which smothers and kills all other vegetation. It is considered to be poisonous to infants and pets that consume it. Also, preliminary tests indicate that when it comes in contact with water, some toxic substance is released that kills fish and other aquatic organisms. In this paper, I present a summary of what is thus far known about Cape ivy's biology, distribution, impacts, and control measures. This should assist in making informed decisions on how to manage this invasive South African vine.
Technical Abstract: Delairea odorata is a vine, native to South Africa, that has demonstrated its invasive nature on three continents, with California and parts of Australia probably being the worst impacted by this South African vine. In California, it has been consistently recognized by environmental groups as one of the worst weeds of natural areas and has been added to that state's "Noxious Weed List". It frequently forms a thick blanket that smothers underlying vegetation, reduces biodiversity, transforms ecosystems, and degrades the utility of infested areas. It is also suspected of being toxic to mammals that ingest it, and to poison aquatic organisms, but evidence for such poisonings is not yet conclusive. It is still readily available as an ornamental, and this is likely to contribute to its further spread.