''Sporobolus foliosus'' is a species of

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and ...

known by the common name California cordgrass. It was reclassified from ''Spartina foliosa'' after a taxonomic revision in 2014. It is native to the

salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominate ...

es and

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...

s of coastal California and

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, especially

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from ...

. It is a perennial grass growing from short

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow ho ...

s. It produces single stems or clumps of thick, fleshy stems that grow up to 1.5 meters tall. They are green or purple-tinged. The long, narrow leaves are flat or rolled inward. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on ...

is a narrow, dense, spike-like stick of branches appressed together, the unit reaching up to 25 centimeters long. The lower spikelets are sometimes enclosed in the basal sheaths of upper leaves. This native plant is seriously threatened by the

invasion An invasion is a military offensive in which large numbers of combatants of one geopolitical entity aggressively enter territory owned by another such entity, generally with the objective of either: conquering; liberating or re-establishing con ...

of its North American Atlantic coast relative smooth cordgrass (''Sporobolus alterniflorus''), which is not native to the Pacific coast. ''S. alterniflorus'' was introduced to San Francisco Bay in the 1970s and it quickly began to hybridize with ''S. foliosus''. Hybrids generally outcompete the native plant and spread rapidly, threatening ''S. foliosus'' with localized extirpation. The two species reproduce at the same time of year, and the invader sheds large amounts of

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophy ...

that fertilize the flowers of the native, so that the majority of an affected native plant's offspring are hybrids. This is an example of

genetic pollution Genetic pollution is a controversial term for uncontrolled gene flow into wild populations. It is defined as "the dispersal of contaminated altered genes from genetically engineered organisms to natural organisms, esp. by cross-pollination", but ...

. ''S. alterniflorus'' × ''foliosus'' hybrids have spread rapidly because they are much more genetically fit than either parental species, an example of

hybrid vigor Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions o ...

.''Spartina foliosa''.
NatureServe. 2012. However, ''S. foliosus'' is still the dominant plant at lower tidal elevations in most salt marshes around San Francisco Bay, and numerous locations within the Bay have remained uninfested during ongoing efforts to eradicate ''S. alterniflorus'' and hybrids. Restoration of

tidal marsh A tidal marsh (also known as a type of "tidal wetland") is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean. Tidal marshes are commonly zoned into lower marshes ...

habitat is in progress at multiple sites, including the planting of cultivated ''S. foliosus'' harvested from uninfested locations and propagated in a nursery.http://spartina.org/documents/2014_5RevegRpt2015_16Plan_20160126_ALLWeb.pdf, Hammond J, San Francisco Estuary Invasive ''Spartina'' Project Revegetation Program Year 4 (2014-2015) Installation Report and Year 5 (2015-2016) Revegetation Plan (DRAFT). Accessed 7/12/18.

References

External links

Calflora: ''Spartina foliosa'' (California cord grass)Jepson Manual (TJM2) TreatmentUSDA Plants Profile for ''Spartina foliosa'' (California cordgrass)San Francisco Estuary Invasive Spartina ProjectGrass Manual Treatment: ''Spartina foliosa''UC CalPhotos gallery
{{Taxonbar, from1=Q91475624, from2=Q7573950 foliosus Native grasses of California Flora of Baja California Grasses of Mexico