California Invasive Plant Council

Dittrichia graveolens

Synonyms: Inula graveolens, Erigeron graveolens, Cupularia graveolens

Common names: stinkwort; stinkweed; Khaki weed;

Dittrichia graveolens (stinkwort) is a fall-flowering, sticky aromatic annual (family Asteraceae) that is native to southern Europe, northern Africa, and southwestern Asia.  It was first recorded in California in 1984 and has rapidly spread across many parts of the state since its introduction. Stinkwort has glandular-haired leaves and stems and grows to a height of up to 0.2 – 1m; its flowers are clustered in small, yellow, flower heads.  It’s leaves are simple, lanceolate to linear-shaped and have an unpleasant odor. Stinkwort favors disturbed areas and can be easily dispersed easily both because it is a prolific seed producer and because minute barbs on the pappus of its propagules aid in dispersal. It is unpalatable to livestock, severely impacts rangelands, and can outcompete native vegetation.

Cal-IPC Rating: Moderate — Alert?

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)

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

• Managing stinkwort. Woolen, Kevin, IPM Specialist, San Francisco Water Enterprise. Vol 28, Issue 1
• FROM THE DIRECTOR’S DESK: Renewing the Cal-IPC Inventory. Johnson, Doug. Vol 25, Issue 2
• Cal-IPC partners to protect military lands. Brusati, Elizabeth. Vol 23, Issue 2
• The volunteer contribution. Cal-IPC. Vol 22, Issue 2
• Mendocino County stops northbound stinkwort. Morse, Chuck. Vol 21, Issue 2
• Stinkwort: history, research, and management. Brownsey, Rachael; Kyser, Guy; DiTomaso, Joseph. Vol 20, Issue 2
• Wildland Weed News. Cal-IPC. Vol 20, Issue 1
• Prioritizing Regional Response to Invasive Plants in the Sierra Nevada. Brusati, Elizabeth; Morawitz, Dana; Powell, Cynthia. Vol 19, Issue 2

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.

• Keeping stinkwort at arm’s length. Flint, Alisa (2022)
• Regional EDRR with Bay Area WMAs. Johnson, Doug; Valentine, Nicole (2022)
• A tale of two wildfires: post-fire weed management at Pepperwood Preserve. Friedfel, Devyn; Halbur, Michelle; Gillogly, Michael; Barringer, Sonja; Comendant, Tosha (2020)
• A test of the herbicide Weed Slayer for the control of invasive plants. Thomas, Don (2020)
• Characteristics of plant communities invaded by Dittrichia graveolens as it spreads away from roadsides in Santa Clara County. Lopez, Andrew; Melen, Miranda; Lustenhouwer, Nicky; Parker, Ingrid (2020)
• Early detection and rapid response: effective weed control at the landscape level. Farrell, Sharon; Patterson, Jesse; Kesel, Rachel; Brigham, Christy; Gregory, Nathan; Gardner, Leah (2020)
• Using climate niche modeling to map areas at risk of invasion by stinkwort (Dittrichia graveolens). Lustenhouwer, Nicky; Parker, Ingrid (2020)
• Evolutionary drivers of the invasion of stinkwort (Dittrichia graveolens) in California. Lustenhouwer, Nicky (2019)
• Successes, failures, and lessons from the Orange County CNPS Emergent Invasive Program. Vanderhoff, Ron (2019)
• Evolution of an invasive plant control program – adoption of early detection and rapid response. Mitrovich, Milan (2018)
• The spread and control of Dittrichia graveolens. Marriott, Meg (2010)
• Weed Alerts 2010. DiTomaso, Joseph (2010)
• 2004 Cal-IPC Red Alert! New invasions, recent expansions, and a few others to be on the look-out for…. DiTomaso, Joseph M. (2004)

Other Dittrichia graveolens 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