''Halophila engelmannii'' is a species of

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...

in the

Hydrocharitaceae Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species (Christenhusz & Byng 2016), that including a number of species of aquatic plant, for instance the tape-grasses, the well known Canadian ...

family. It is referred to by the common names star grass and Engelmann's seagrass and grows underwater on shallow sandy or muddy sea floors. It is native to the

Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the ar ...

, the Cayman Islands, Costa Rica,

Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...

, the Gulf Coast of the United States, the Gulf Coast of Mexico,

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...

, and

Trinidad and Tobago Trinidad and Tobago (, ), officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean. Consisting of the main islands Trinidad and Tobago, and numerous much smaller islands, it is situated south of ...

Description

Halophila ''Halophila'' is a genus of seagrasses in the family ''Hydrocharitaceae'', the tape-grasses. It was described as a genus in 1806. The number of its contained species, and its own placement in the order Alismatales, has evolved. Description Th ...

is the only genus of seagrass lacking basal sheaths on the leaf stems. Like other seagrasses, ''Halophila engelmannii'' has rhizomes that run along near the surface of sand or mud, with roots at the nodes to anchor them in place. Each leaf stem grows from a node and has a pair of scales halfway up and another pair at the base of the leaf blades. There are 4 to 8 blades on each stem, each of which is up to long and wide. Each blade is oval, has 6 to 8 veins and a finely serrated margin.

Distribution

''Halophila engelmannii'' is found on the coasts of

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

, the

and the

West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greate ...

. It can grow in deeper waters than do some other species of seagrass, at depths down to . It is one of three species of ''

'' found in the Indian River Lagoon, Florida, the others being ''

Halophila decipiens ''Halophila decipiens'', commonly known as Caribbean seagrass or paddle grass, is a seagrass in the family Hydrocharitaceae. It grows underwater on sandy or muddy sea floors in shallow parts of tropical seas. Description ''Halophila'' is the onl ...

'' and '' Halophila johnsonii''. They often form mixed

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s at greater depths than other seagrasses normally grow.''Halophila engelmannii'' (Star grass)
Smithsonian Marine Station at Fort Pierce. Retrieved 2012-01-28.

Biology

Flowering occurs in the early summer when the water temperature reaches at least 22 °C. Fragments of the plant that become detached are able to grow into new plants. The seagrass meadow acts as habitat and food source for many invertebrates and fish. In the Indian River Lagoon, animals that feed on ''Halophila engelmannii'' include

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...

s, sea urchins,

parrotfish Parrotfishes are a group of about 90 fish species regarded as a family (Scaridae), or a subfamily (Scarinae) of the wrasses. With about 95 species, this group's largest species richness is in the Indo-Pacific. They are found in coral reefs, ro ...

, surgeonfish and possibly

pinfish ''Lagodon'' is a genus of saltwater fish in the family Sparidae, the breams and porgies. It is monotypic, being represented by the single species ''Lagodon rhomboides'', commonly known as pinfish.Masterson, J''Lagodon rhomboides''.Smithsonian Mar ...

. The sea slug '' Elysia serca'' preferentially feeds on it by sucking sap.''Elysia serca''
Smithsonian Marine Station at Fort Pierce. Retrieved 2012-01-28.

References

{{Taxonbar, from=Q5643432 engelmannii Flora of the Bahamas Flora of the Cayman Islands Flora of Costa Rica Flora of Cuba Flora of the United States Flora of Mexico Flora of Puerto Rico Flora of Trinidad and Tobago Taxa named by Paul Friedrich August Ascherson Flora without expected TNC conservation status