vs Coastal Ragweed

Chrysosphaerella triangulata 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	Ochromonadales (Ochromonadales)	Asterales (Daisies & Sunflowers)
Family	Paraphysomonadaceae	Asteraceae (Daisy Family)
Genus	Chrysosphaerella	Ambrosia
Species	Chrysosphaerella triangulata	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.

Chrysosphaerella triangulata is a colonial freshwater chrysophyte microalga in the genus Chrysosphaerella, class Chrysophyceae, order Chromulinales. Chrysosphaerella species form spherical free-floating colonies of golden-brown cells embedded in a gelatinous matrix, with individual cells bearing elongated siliceous scales that project outward from the colony surface. The species epithet triangulata — triangular — refers to the triangular cross-section or profile of the siliceous scales on the cell surface, which distinguishes this species from C. annulata, which has annular ring structures on its scales, and from other congeners with different scale geometries. Siliceous scale morphology examined under scanning electron microscopy is the primary diagnostic character for Chrysosphaerella species identification. C. triangulata has been recorded from Norwegian and Swedish freshwater habitats, part of the documented chrysophyte flora of boreal and subarctic Scandinavian lakes. These environments are characterized by cold, clear, nutrient-poor water and seasonal ice cover, creating conditions favorable for chrysophyte diversity including colonial forms like Chrysosphaerella. The colonies inhabit the photic zone of the water column, photosynthesizing with chlorophylls a and c and carotenoid accessory pigments. Chrysosphaerella scales deposited in lake sediments serve as paleolimnological indicators. C. triangulata has not been formally evaluated under IUCN criteria and is listed as Not Evaluated. It contributes to documentation of the rich chrysophyte diversity in Scandinavian freshwater 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.