vs Coastal Ragweed

Chrysolykos complanatus compared with Ambrosia hispida

Key Differences

• is Not Evaluated while Coastal Ragweed is Least Concern.

Taxonomic Classification

Rank		Coastal Ragweed
Kingdom	Chromista (Chromista)	Plantae (Plants)
Phylum	Ochrophyta (Ochrophyta)	Magnoliophyta (Flowering Plants)
Class	Chrysophyceae (Chrysophyceae)	Magnoliopsida (Dicots)
Order	Chromulinales (Chromulinales)	Asterales (Daisies & Sunflowers)
Family	Dinobryaceae	Asteraceae (Daisy Family)
Genus	Chrysolykos	Ambrosia
Species	Chrysolykos complanatus	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

Distributed across Norway and Sweden.

Coastal Ragweed

Habitat

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

Range

Found in Cuba.

Chrysolykos complanatus is a freshwater chrysophyte microalga in the genus Chrysolykos, class Chrysophyceae. The species epithet complanatus — flattened or compressed — describes a lorica that is notably flattened in lateral view compared with the more three-dimensional forms of other Chrysolykos species. This flattened lorica morphology is the primary taxonomic character distinguishing C. complanatus from the angular C. angulatus and the boot-shaped C. calceatus within the small genus Chrysolykos. The loricate chrysophytes, including Chrysolykos, are characterized by cells enclosed within a species-specific outer case from which two flagella emerge — one directed anteriorly and one often wrapped around the cell — enabling swimming in aquatic environments. C. complanatus has been recorded from Norwegian and Swedish freshwater ecosystems, contributing to the known diversity of chrysophytes in cold Scandinavian lakes and pond habitats. These boreal and subarctic freshwater environments, often characterized by low pH, low nutrient concentrations, and high dissolved organic carbon from surrounding peat bogs, support characteristic chrysophyte assemblages in which loricate forms are frequently present. The species contributes to primary production as a photoautotroph and may supplement its carbon budget through bacterivory. Chrysolykos species are minor components of most phytoplankton communities and are not known to form blooms. C. complanatus has not been evaluated under IUCN Red List criteria and is listed as Not Evaluated.

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.