California Invasive Plant Council

Delairea odorata

Synonyms: Senecio mikanioides

Common names: Cape-ivy; German ivy; Italian ivy; ivy groundsel; parlor ivy; water ivy

Delairea odorata (=Senecio mikaniodes) (Cape-ivy, German-ivy) is a perennial vine (family Asteraceae) found along the coast of California and in the San Gabriel Mountains. Cape-ivy is especially problematic in coastal riparian areas, though it may also invade inland riparian areas, moist forests, and oak woodlands. Vines are known to form dense mats of vegetation over trees and shrubs, killing plants underneath. It is toxic to animals and fish can be killed when plant materials are soaking in waterways. Stem, rhizome and stolon fragments resprout if left in the ground after treatment. Can occasionally reproduce by seeds in some areas.

Cal-IPC Rating: High?

Explanation of Cal-IPC ratings

• High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
• Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
• Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
• Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
• Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.

CDFA Rating: -*?

Explanation of CDFA ratings

• A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
• B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
• C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
• D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
• Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
• * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
• -* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.

More details

Assessment(s)

Delairea odorata Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Species ID Card

Invasive Species ID Card - To support field identification of early detection species, Cal-IPC has designed a set of Species ID cards that can be downloaded, printed double-sided, and trimmed to size.

Weed Management Notes

• Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

• Cape-ivy falling fly established and thriving along the California Coast. Portman, Scott L.; Moran, Patrick J.. Vol 28, Issue 2
• Municipal compost and wildland weeds. Near, Hilary; Meyler, Claire. Vol 26, Issue 3
• First biological control agent released against Cape-ivy. Moran, Patrick J.; Portman, Scott L.. Vol 25, Issue 1
• Weed biological control agents approved for California. Pitcairn, Michael J.; Smith, Lincoln; Moran, Patrick. Vol 22, Issue 1
• Cape-ivy Biocontrols Update. Reddy, Angelica M; Mehelis, Chris. Vol 19, Issue 2
• CNPS removes weeds at Pt. Cabrillo. Abreu, Mario. Vol 17, Issue 3
• Tackling invasive plants on California Sept. of Fish & Game lands. O'Rourke, Brianne; Horenstein, Julie. Vol 17, Issue 1
• East Bay volunteers head to the hills and the shores. Schwartz, Susan. Vol 16, Issue 4
• Predicting plant invasion with modeling. Steinmaus, Scott. Vol 10, Issue 1
• Help needed in collecting more seed: Cape ivy germinating in California and Oregon. Robison, Ramona. Vol 09, Issue 3
• Cautionary note for land managers & stewards: Viable seed production by cape ivy in California finally confirmed. Balciunas, Joe. Vol 09, Issue 2
• Biological control of cape ivy project reaches milestone. Balciunas, Joe. Vol 09, Issue 1
• Exotic pest plants, Calif. Assoc. of Nurserymen, and CalEPPC. Bell, Carl E.; Evans, Mike; Wilen, Cheryl. Vol 09, Issue 1
• Test plants needed for biocontrol of cape ivy project. Balciunas, Joe. Vol 09, Issue 1
• Roundup of Arundo projects reveals commitment, strategic weakness. Kelly, Mike. Vol 07, Issue 2
• Richmond weed abatement ordinance. . Vol 07, Issue 1
• Results of the CalEPPC questionnaire at Symposium ’98 in Ontario. DiTomaso, Joe. Vol 06, Issue 4
• Some tips on herbicide treatment of cape ivy (Delairia odorata). Fobert, Mike. Vol 06, Issue 2
• CalEPPC Symposium ’97. Warner, Peter. Vol 06, Issue 1
• Battling the Kudzu of the west: Controlling cape ivy (formerly German ivy) by hand removal. Moore, Ken. Vol 05, Issue 4
• Lessons from the front: Taking stock to avoid surprises. Kelly, Mike. Vol 05, Issue 1
• Weed alert!. Cal-IPC. Vol 03, Issue 3
• Exotic pest plants of greatest ecological concern in California September 1994. Cal-IPC. Vol 02, Issue 4
• German ivy engulfing riparian forests and heading for the uplands. Elliott, Woody. Vol 02, Issue 1
• Working group reports on weed control methods and applications for Arundo, french broom, german ivy, hoary cress, yellow starthistle, and pampasgrass. Cal-IPC. Vol 01, Issue 3
• German ivy infestation in San Luis Obispo. Chipping, David. Vol 01, Issue 1

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

• Biological control agents of weeds in California: Overview of rearing, releases, and monitoring by the CDFA Biological Control Program. Moran, Patrick (2023)
• Update on recent biological control releases against invasive plants by the USDA-ARS. Moran, Patrick; Pratt, Paul; Smith, Lincoln (2022)
• Challenges and lessons learned in the Muir Beach wetland restoration project. LeBeau, Naomi (2020)
• First field release of the Cape-ivy shoot tip-galling fly along the California coast. Portman, Scott; Moran, Patrick (2018)
• Mapping weeds and rare plants to inform management and conservation in the Zaca and Jesusita fires. Calloway, Stephanie; Schneider, Heather; Knapp, Denise (2018)
• New biocontrol releases and integrated control targeting Cape-ivy in riparian areas. Portman, Scott (2017)
• An assessment of control methods for cape ivy in Central California coastal riparian ecosystems. Stern, Jennifer; Watson, Fred (2008)
• Eradicating 25 species- Challenges and successes of switching from population to seed bank management on Catalina Island, California. Knapp, John; Ratay, Sarah; Hall, Jon (2007)
• A test of repeat flaming as a control for poison hemlock (Conium maculatum), Cape ivy (Delairea odorata), and periwinkle (Vinca major). Bossard, Carla; Moore, Ken; Chabre, Cammy; Woolfolk, Andrea; King, Jorden; Johanek, Dana (2005)
• Reproductive biology of cape ivy (Delairea odorata) in California. Robison, Ramona (2004)
• Riparian working group. Giessow, Jason; Newhowser, Mark (2004)
• Biocontrols: Progress and ongoing needs. Carruthers, Ray; Buettner, Joel (2003)
• Manual removal of cape ivy in Volunteer Canyon Bolinas Lagoon Preserve, Audubon Canyon Ranch, Stinson Beach, California. Blumin, Len; Gluesenkamp, Daniel (2002)
• Management of cape-ivy (Delairea odorata) in the Golden Gate National Recreation Area. Alvarez, Maria E. (1997)
• Stewardship and resource education at the Presidio. Farrell, Sharon (1997)
• Using Transline* herbicide to control invasive plants. Carrithers, Vanelle F. (1997)
• Volunteers and long-term community support for effective pest plant control. Moore, Ken; Hayes, Grey; Grey, (1995)
• War on German ivy: good news from the front. Bossard, Carla C.; Benefield, Carrie (1995)

Other Delairea odorata Information

• CalPhotos - Images of plants taken mostly in California.
• Calflora - Distribution map and records of this species in California.
• CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
• EDDMapS - Distribution of this species in North America.
• Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
• USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.

Additional photos