Ranges from San Diego County to Baja California [1,2].
Known Populations in San Diego County
Native populations restricted to Coastal San Diego County . Occurrences found on Conserved Lands in MUs 3,4, and 6 (Lusardi Creek Preserve and Escondido Creek).
Grows in marshes, swamps, and playas [1,2]. Alkaline flats, depressions, alkali marshes, sinks [4,5]. Salt and freshwater marshes and ecotones with coastal sage scrub .
Taxonomy and genetics
In the Asteraceae family [1,2].
Life history demography
A perrenial herb . Seeds are small, less than 2 mm long and spindle-shaped .
Blooms from April to October .
Pollination seed dispersal
Tiny achenes are likely dispersed by a combination of gravity, wind, and water as are related species of Asteracae .
Threatened by waterway channelization, coastal development [1,2], vehicles, and nonnative plants .
San Diego marsh-elder sources
 California Native Plant Society, Rare Plant Program. 2017. Inventory of Rare and Endangered Plants of California (online edition, v8-03 0.39). Website http://www.rareplants.cnps.org [accessed 29 September 2017].
 NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed: September 29, 2017 ).
 Montalvo, A. M., L. K. Goode, and J. L. Beyers. 2010. Plant Profile for Iva hayesiana. Native Plant
Recommendations for Southern California Ecoregions. Riverside-Corona Resource Conservation District and
U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, Riverside, CA. Online:
 Munz, P. A. 1974. A Flora of Southern California. University of California Press, Berkeley, CA.
 Hickman, J. C. 1993. The Jepson Manual: Higher Plants of California. University of California
Press, Ltd., Los Angeles, CA."
 Boczkiewicz, S. 2005. Biological Resources Report for the 2005 SDSU Campus Mater Plan
Revision, San Diego, California. Dudek and Associates, Inc. for San Diego State
University, San Diego, CA. "