vs Coastal Ragweed

Chrysococcus cordiformis 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	Chrysococcus	Ambrosia
Species	Chrysococcus cordiformis	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 Denmark, Norway, and Sweden.

Coastal Ragweed

Habitat

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

Range

Found in Cuba.

Chrysococcus cordiformis is a freshwater chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae. The species epithet cordiformis — heart-shaped — describes the characteristic lorica shape of this species, a lorica being the rigid or semi-rigid outer case secreted by the cell that gives Chrysococcus its distinctive appearance. The heart-shaped lorica of C. cordiformis provides a clear morphological character distinguishing it from species with spherical, ovoid, or otherwise shaped loricas. Chrysococcus species are unicellular, loricate golden algae that inhabit freshwater ecosystems, particularly the euphotic zones of oligotrophic to mesotrophic lakes and ponds. C. cordiformis has been documented from Norwegian and Swedish freshwater environments, which provide cold, clear-water habitats typical of Scandinavian highland and boreal lakes. Records also extend to Brazil, indicating a wide geographic range consistent with the passive dispersal capacity of small, light-weight planktonic microalgae. The cells of C. cordiformis possess one or two flagella that protrude through an opening in the lorica, enabling active swimming in the water column. Photosynthesis is conducted using chlorophylls a and c with carotenoid accessory pigments. Chrysococcus species may also feed phagotrophically on bacteria. C. cordiformis has not been formally evaluated under IUCN criteria and retains a conservation status of Not Evaluated. It represents a characteristic member of freshwater chrysophyte communities associated with cool, acidic, or nutrient-poor Scandinavian lake systems.

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.