vs Coastal Ragweed

Chroomonas placoidea 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	Cryptophyta	Magnoliophyta (Flowering Plants)
Class	Cryptophyceae (Cryptophyceae)	Magnoliopsida (Dicots)
Order	Pyrenomonadales (Pyrenomonadales)	Asterales (Daisies & Sunflowers)
Family	Chroomonadaceae	Asteraceae (Daisy Family)
Genus	Chroomonas	Ambrosia
Species	Chroomonas placoidea	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.

Chroomonas placoidea is a species of cryptophyte alga in the family Chroomonadaceae, documented from freshwater and aquatic environments in Europe. The specific epithet placoidea may refer to a flattened or plate-like aspect of the cell morphology, from the Greek plakos meaning flat plate. Cryptophyte cells are frequently compressed or dorsiventally flattened, and small differences in cell shape and proportions are important characters for distinguishing species within the morphologically subtle genus Chroomonas. Chroomonas species are characterized by small cell size, typically ranging from five to twenty micrometers in length, with two flagella of unequal length arising from a ventral depression. The plastid occupies much of the cell volume and contains photosynthetically active pigments including chlorophyll a, chlorophyll c, and phycobiliproteins. Chroomonas placoidea contributes to primary production in its freshwater habitat and is part of the diverse microalgal community of European lakes and ponds. Like other cryptophytes, it may engage in mixotrophy under some conditions. The species has not been assessed by the IUCN, consistent with the general treatment of microalgal organisms in conservation frameworks.

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.