Synonyms: Iris acoriformis, Iris bastardi, Iris curtopetala, Iris lutea, Iris paludosa
Common names: yellowflag iris; pale yellow iris
Iris pseudacorus (yellowflag iris) (family Iridaceae) invades wetlands and meadows along coastal California and some inland counties. Iris pseudacorus is a fast-growing and rapidly-spreading invasive plant that can out-compete other wetland plants, forming almost impenetrable thickets, in much the same way as cattails do.Cal-IPC Rating: Limited
CDFA Rating: B
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
- PlantRigh update: Nursery survey and plant list. Falzone, Stephanie. Vol 25, Issue 3
- Protecting San Diego wetlands. Cal-IPC. Vol 24, Issue 1
- Wildland Weed News. Cal-IPC. Vol 22, Issue 2
- Don’t sell a pest: A new partnership to prevent plant invasions through horticulture. Connick, Sarah; Gerel, Mike. Vol 13, Issue 2
- Roundup of Arundo projects reveals commitment, strategic weakness. Kelly, Mike. Vol 07, 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.
- Iris pseudacorus germination resilience to high salinity exposure supports risk of invasive spread in tidal wetlands. Gillard, Morgane; Castillo, Jesus; Mesgaran, Mohsen; Futrell, Caryn; Grewell, Brenda (2020)
- Exploring the germination ecology of Iris pseudacorus populations invading California wetlands. Gillard, Morgane B.; Castillo, Jesús M.; Mesgaran, Mohsen; Futrell, Caryn J.; Grewell, Brenda J. (2019)
- High salinity exposure does not preclude germination of invasive Iris pseudacorus from populations along a Delta-San Francisco Estuary salinity gradient. Gillard, Morgane (2019)
- Partnering to prevent invasions of plants of horticultural origin. Connick, Sarah; Gerel, Mike (2004)
Other Iris pseudacorus 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.
- Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
- EDDMapS - North American distribution based on Early Detection and Distribution Mapping System.