vs Coastal Ragweed

Chroococcus giganteus compared with Ambrosia hispida

Key Differences

• is Not Evaluated while Coastal Ragweed is Least Concern.

Taxonomic Classification

Rank		Coastal Ragweed
Kingdom	Bacteria (Bacteria)	Plantae (Plants)
Phylum	Cyanobacteria (Cyanobacteria)	Magnoliophyta (Flowering Plants)
Class	Cyanobacteriia	Magnoliopsida (Dicots)
Order	Cyanobacteriales	Asterales (Daisies & Sunflowers)
Family	Microcystaceae	Asteraceae (Daisy Family)
Genus	Chroococcus	Ambrosia
Species	Chroococcus giganteus	Ambrosia hispida

Conservation Status

NE — Not Evaluated

Coastal Ragweed

LC — Least Concern

Physical Characteristics

Attribute		Coastal Ragweed
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Found in Sweden.

Coastal Ragweed

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Found in Cuba.

Chroococcus giganteus is a species of cyanobacteria in the family Chroococcaceae, notable for being among the largest-celled representatives of its genus, as indicated by the specific epithet. While cyanobacterial cells are generally microscopic, there is considerable variation in cell size within the genus Chroococcus, and giganteus refers to its relatively large cell diameter compared to other species in the group. Chroococcus cells are spherical to hemispherical, typically dividing by binary fission to form pairs or groups of two to four cells enclosed within layered mucilaginous sheaths. The photosynthetic pigments in the cells give them a blue-green to olive coloration. Chroococcus giganteus has been documented from freshwater and moist terrestrial habitats in various geographic regions. As a cyanobacterium, it contributes to primary production in its habitat and potentially to nitrogen cycling if it possesses nitrogen-fixing capacity. Taxonomic resolution within the genus Chroococcus remains challenging due to the limited morphological complexity of these organisms and the significant influence of environmental conditions on cell size and sheath development. The species has not been assessed by the IUCN.

Coastal Ragweed

Coastal ragweed (Ambrosia hispida) is a perennial herb in the family Asteraceae, native to the coastal dunes, sandy beaches, and cays of Cuba, the Bahamas, and the wider Caribbean region. It grows in pioneer beach and dune vegetation, often forming spreading colonies that help stabilise loose coastal sands. Like other members of the genus Ambrosia, it bears inconspicuous greenish-white flowers arranged in racemes; male flower heads produce wind-dispersed pollen that can trigger allergic rhinitis in sensitive individuals. The deeply lobed, hispid leaves are adapted to reflect intense solar radiation and tolerate salt spray. Coastal ragweed plays an ecological role in early dune succession, binding sand and enabling other plant species to establish. The genus is widespread globally, with several Ambrosia species considered noxious weeds in agricultural settings, though Ambrosia hispida is restricted to its native Caribbean coastal range. The IUCN assesses it as Least Concern, reflecting adequate population size across its Caribbean coastal distribution. Pressure from coastal development and tourism infrastructure poses a localised threat to dune communities it inhabits.