Spartina densiflora
Encyclopedia
Spartina densiflora is a species of grass
known by the common name dense-flowered cordgrass. It is native to the coastline of southern South America, where it is a resident of salt marsh
es. It is also known on the west coast of the United States and parts of the Mediterranean coast
as an introduced species
and in some areas a noxious weed. In California
it is a troublesome invasive species
of marshes in San Francisco Bay
and in Humboldt Bay
, where it was introduced during the 19th century from Chile
in ballast
.
s. It grows in erect clumps of slender stems that can reach 1.5 meters tall. The long, narrow, gray-green leaves are rolled inward, especially when new. The inflorescence
is a narrow, dense, spike-like stick of branches appressed together, the unit reaching up to 30 centimeters long. The flowers are colorless and the spikelets are tipped with bristles.
accumulation. It competes with its native relative, California cordgrass
(Spartina foliosa), and other marsh plants such as pickleweed
(Salicornia virginica).
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
known by the common name dense-flowered cordgrass. It is native to the coastline of southern South America, where it is a resident of salt marsh
Salt marsh
A salt marsh is an environment in the upper coastal intertidal zone between land and salt water or brackish water, it is dominated by dense stands of halophytic plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh...
es. It is also known on the west coast of the United States and parts of the Mediterranean coast
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
as an introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
and in some areas a noxious weed. In California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
it is a troublesome invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
of marshes in San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
and in Humboldt Bay
Humboldt Bay
Humboldt Bay is a natural bay and a multi-basin, bar-built coastal lagoon located on the rugged North Coast of California, United States entirely within Humboldt County. The regional center and county seat of Eureka and the college town of Arcata adjoin the bay, which is the second largest enclosed...
, where it was introduced during the 19th century from Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
in ballast
Ballast tank
A ballast tank is a compartment within a boat, ship or other floating structure that holds water.-History:The basic concept behind the ballast tank can be seen in many forms of aquatic life, such as the blowfish or argonaut octopus, and the concept has been invented and reinvented many times by...
.
Description
This perennial grass generally lacks rhizomeRhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
s. It grows in erect clumps of slender stems that can reach 1.5 meters tall. The long, narrow, gray-green leaves are rolled inward, especially when new. The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a narrow, dense, spike-like stick of branches appressed together, the unit reaching up to 30 centimeters long. The flowers are colorless and the spikelets are tipped with bristles.
Invasive species
This plant has negative impacts on the salt marsh habitat of the California coast. It forms tight clumps of herbage that raise the elevation of the plants in the marsh, keeping the water from flowing in as far as it naturally would, and increasing sedimentSediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
accumulation. It competes with its native relative, California cordgrass
Spartina foliosa
Spartina foliosa is a species of grass known by the common name California cordgrass. It is native to the salt marshes and mudflats of coastal California and Baja California, especially San Francisco Bay. It is a perennial grass growing from short rhizomes. It produces single stems or clumps of...
(Spartina foliosa), and other marsh plants such as pickleweed
Salicornia virginica
Salicornia virginica is a halophytic perennial dicot which grows in various zones of intertidal salt marshes and can be found in alkaline flats...
(Salicornia virginica).