Coastal Ragweed vs Flat Crep

Ambrosia hispida compared with Crepidotus applanatus

Key Differences

Coastal Ragweed is Least Concern while Flat Crep is Vulnerable.

Taxonomic Classification

Rank	Coastal Ragweed	Flat Crep
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Basidiomycota (Club Fungi)
Class	Magnoliopsida (Dicots)	Agaricomycetes (Mushrooms)
Order	Asterales (Daisies & Sunflowers)	Agaricales (Gilled Mushrooms)
Family	Asteraceae (Daisy Family)	Crepidotaceae
Genus	Ambrosia	Crepidotus
Species	Ambrosia hispida	Crepidotus applanatus

Conservation Status

Coastal Ragweed

LC — Least Concern

Flat Crep

VU — Vulnerable

Physical Characteristics

Attribute	Coastal Ragweed	Flat Crep
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Ragweed

Habitat

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

Range

Found in Cuba.

Flat Crep

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Europe (5 countries), North America (United States), and South America (Brazil). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.