Salt-Marsh Bird’s Beak

Text by Margie Mulligan

Photos by Jon Rebman and Margie Mulligan

Amongst the salt marsh plants not far from the water’s edge grows an unassuming plant that doesn’t exclusively use chlorophyll to make food. In addition to photosynthesis, this special plant employs a unique strategy of parasitizing its companion plants by extending a slender projection (haustorium) from its roots penetrating the tissue of its host stealing its nutrients. Salt Marsh Bird’s Beak or its scienti- fic name Chloropyron maritimum ssp. maritimum is not a showy plant, however it is particular about its habitat.

It is halophytic, salt-tolerant plant and grows in soils of high salinity, similar to the other salt marsh plants. However, this taxon, unlike its companions, appears to need a perfect combination of fresh and salt water to survive.

This unusual annual plant is in the Orobanchaceae or Broomrape Family and formerly described under the name Cordylanthus maritimus ssp. maritimus. Many plants in this family are also hemiparasitic, possessing chlorophyll but deriving some or all of their nutrients from other living plants. Some of these taxa are host-specific and use particular plant species that are in close proximity. Salt Marsh Bird’s Beak is not host specific and will use a variety of plants found nearby.

Some of the commonly associated plants include Distichlis littoralis, Frankenia salina, Batis maritima, Salicornia bigelovii, S. pacifica and Limonium californicum. Interestingly, scientists have been able to grow this taxon in a lab without any hosts showcasing its photosynthetic abilities (Chuang and Eckard, 1973).

Salt Marsh Bird’s Beak occurs in disjunct salt marshes ranging from Morro Bay, California, in the north to its southern extent in San Quintín, Baja California. It is considered a rare plant in Mexico listed as threatened (Amenazada in Spanish), a species that could be in danger of disappearing in the short or medium term, in the official Mexican Standard NOM-059-SEMARNAT-2010. It is also listed in the U.S. as Endangered, considered in danger of extinction throughout all or a significant portion of its range.

Fortunately, in Baja California most of the populations occur on Terra Peninsular managed lands near Bahía de San Quintín and Bahía Falsa where habitat is protected.

A new location was brought to our attention via iNaturalist observations by Pro Esteros at Estero Punta Banda in Ensenada. This locality was not mentioned in the literature or known amongst Botanists studying this taxon. Digging deeper into this location, we were able to find a 2008 collection listed under the old name of Cordylanthus. Historically, there were populations that occurred north of San Quintín at Bahía de San Ramon and San Telmo but these have not been observed in recent years. This new locality is exciting to scientists because it bridges the gap between San Quintín and its nearest population in Tijuana Slough in San Diego.

Population size numbers appear to be relatively small compared to San Diego populations. In 2017, scientists from the San Diego Natural History Museum found populations in San Quintín ranged from 50 to 100 plants with a total occurrence size of 300 plants. That same year San Diego populations supported a total of 25,000 plants. Salt Marsh Bird’s Beak populations do fluctuate wildly year to year most likely influenced by changes in rain fall and/or storm surges. In 2008, Sula Vanderplank (2011) observed populations in the 10,000s in several patches at Bahía de San Quintín and she also reported good spring rains.

Climate change is a threat to these populations across its range. Rising ocean levels and increase in and severity of storm surges makes these populations vulnerable, especially in Mexico. Populations are often within 50 feet of shore with no barriers for protection, and reduction of freshwater due to drought conditions could change salinity in some areas. Current populations should be monitored closely to mark any significant declines in population numbers. As a precaution, with genetic studies as a guide, seed should be collected to preserve the diversity of these populations.

This is a call to fellow Botanists and naturalists to find additional populations especially in areas where it was previously known, such as San Ramón and San Telmo. Looking through aerial photos on Google Earth, I can see several disjunct salt marshes between Ensenada and San Quintín and this doesn’t necessarily include the degraded locations where this taxon may still persist. All observations can be documented through the iNaturalist app at inaturalist. org or feel free to email locality info directly to mulliganbiocon@gmail.com. With community support, we could increase the range of this taxon in Mexico.

Thanks to Terra Peninsular for continuing to protect habitat for Mexico’s rare species such as Salt Marsh Bird’s Beak. Their work in the salt marshes of San Quintín has been integral to preserving this plant in Baja California.

Ms. Mulligan is an independent Botanist and a Department Associate in the Botany Department at the San Diego Natural History Museum. She has over 24 years of botanical experience with 14 years, specifically in San Diego County and northern Baja California. She holds a BS in Environmental Studies (Biophysical) from Northland College and an MS in Botany from Miami University of Ohio. She specializes in floristics and rare species of San Diego County and has a strong interest in northern Baja California flora. She is a founding member of San Diego Botanical Society and teaches a botanical field course at San Diego State University.

●Chuang, T. I. and L. R. Heckard. 1973. Taxonomy of Cordylanthus subgenus Hemistegia (Scrophulariaceae). Brittonia 25: 135–158.

●The Flora of Baja California. 2019. http://bajaflora.org [accessed on 10 Jan 2019].

●Vanderplank, S. E. 2011. Rare plants of California in Greater San Quintín, Baja California, Mexico. In Proceedings of the CNPS conservation conference: strategies and solutions. California Native Plant Society Sacramento: 381-387.