vs Coastal Ragweed

Chrysosphaerella longispina 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 longispina	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.

Chrysosphaerella longispina is a colonial chrysophyte alga in the genus Chrysosphaerella, notable for the long silica spines (longispina: Latin, long spine) that project from each cell in the colony. The genus is characterized by spherical or discoid colonies of photosynthetic cells that each secrete siliceous scales and elongated spine-like appendages, making Chrysosphaerella colonies distinctively bristled and visible under light microscopy. The long spines of C. longispina likely serve as anti-predation structures that make the colonies more difficult for zooplankton to ingest. C. longispina is found in cold, oligotrophic freshwater lakes, particularly in Scandinavia, where comprehensive chrysophyte surveys have documented its presence. Chrysosphaerella colonies contribute to freshwater primary production and the cycling of biogenic silica, which upon cell dissolution is deposited in lake sediments as microscopically identifiable remains. These silica structures are widely used by paleolimnologists to reconstruct past changes in lake water chemistry, thermal stratification, and climate. The conservation status of C. longispina has not been assessed by the IUCN; the species 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.