Family: Cuscutaceae (Dodder Family)
Duration and Habit: Annual Vine
Japanese dodder is an annual, parasitic vine that has recently been introduced into the United States. Japanese dodder is listed as a Federal Noxious Weed. The stems are fleshy, circular, pale yellow with red spots and striations, and much branched. Leaves are minute and scale-like. Flowers are abundant, pale yellow, and sessile. Many species of dodder, some native and some exotic, occur in the United States. Japanese dodder parasitizes host plants by penetrating the vascular tissue of the host with structures called haustoria. Severe infestations can kill host plants. Japanese dodder is native to Asia and several infestations in Texas, Florida, and South Carolina have recently been found.
Ecological Threat: This parasite threatens native vegetation by killing host seedlings or by making host trees more susceptible to disease. Poses a threat to crops such as alfalfa, asparagus, and tomatoes, in addition to horticultural plants.
Biology & Spread: Germinates in the spring near the soil surface. Flowers in late summer and fruits in early fall. A single plant can produce over 2,000 seeds, which remain viable for up to 20 years. Also reproduces via fragmentation and attachment to a new host. Grows very rapidly, up to 6 inches/day. As a parasitic vine that penetrates the vascular tissue of its host for water and nutrients, it reattaches to the host plant as it grows. Once established, its connection to the soil terminates.
History: Discovered in residential areas of Houston near Hobby Airport in 2001 after being introduced to and eradicated from several southern states in the 1970s. Most likely enters as seed in the soil of other imported plants.
U.S. Habitat: Capable of growing in a wide range of environments; found in fencerows, abandoned land, and residential yards, attacking trees and bushes.
U.S. Nativity: Introduced to U.S.
Native Origin: Introduced to U.S.
U.S. Present: FL, SC, TX
Distribution: Currently only reported in Texas, South Carolina, and Florida. In the Galveston Bay watershed, reported as infesting trees and bushes in suburban areas of southeast Houston.
List All Observations of Cuscuta japonica reported by Citizen Scientists
This is a parasitic plant. There are no native species alternatives. Restore an affected area by replacing plant species killed by Japanese dodder.
The methods used to control or eradicate dodder consist of post-emergence herbicides, pre-emergence herbicides, injected herbicides, roguing, and eradicative pruning.
1. Pre-emergent herbicides are used to prevent dodder seeds from germinating and seedlings from parasitizing available host plants.
2. Post-emergent herbicides may be used in conjunction with roguing infected plants, removing host material, and eradicative pruning. The post-emergent herbicides effectively kill the dodder in place, so the potential for spread of the parasite during host plant removal and transport is minimized. When utilizing eradicative pruning, such as in managed landscapes, a barrier treatment should be implemented as well. When possible, remove plants that are within 10 feet of the dodder -infected plants in order to create a host free barrier.
3. Herbicides injected into infected host plants are used in some locations when large trees are being attacked by the dodder or other unique difficulties are posed in safely dealing with the disease. A large tree will increase the likelihood of fragmentation and dispersal of the parasite while the host is being felled and cut for transport. Therefore, trees injected with systemic herbicides will rapidly kill the tree and the attached parasite.
Miller, J.H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and control. Gen. Tech. Rep. SRS-62. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 93 pp (USDA SRS).
The Quiet Invasion: A Guide to Invasive Plants of the Galveston Bay Area. Lisa Gonzalez and Jeff DallaRosa. Houston Advanced Research Center, 2006.
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