Synonyms: Rumex spinosus
Common names: devil's thorn; spiny threecornerjack
Emex spinosa (spiny emex, devil’s-thorn) is an annual (family Polygonaceae) found on California’s south coast. This Mediterranean native is not yet common in California, but it is spreading rapidly and is known to crowd out native species. It frequently infests disturbed areas, especially in coastal habitats. Emex spinosa’s spiny seed pods stick to people and animals, so it spreads quickly along trails and then into undisturbed areas.Cal-IPC Rating: Moderate — Alert
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
- Taking to the air to locate, prioritize and treat effectively. Burger, Jutta C.. Vol 21, 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.
There are no Symposium presentations associated with this species yet.
Other Emex spinosa Information
- CalPhotos - Images of plants taken mostly in California.
- Calflora - See the distribution of this species on Calflora's map of California.
- CalWeedMapper - Distribution information with ability to determine regional priorities.
- Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
- USDA PLANTS Database - Federal database with information on identification and distribution, and links to websites in individual states.
- EDD MapS - North American distribution based on Early Detection and Distribution Mapping System.