Coastal Ragweed vs Common Fleabane

Ambrosia hispida compared with Erigeron philadelphicus

Key Differences

• Coastal Ragweed is Least Concern while Common Fleabane is Not Evaluated.

Taxonomic Classification

Rank	Coastal Ragweed	Common Fleabane
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Magnoliopsida (Dicots)	Magnoliopsida (Dicots)
Order same	Asterales (Daisies & Sunflowers)	Asterales (Daisies & Sunflowers)
Family same	Asteraceae (Daisy Family)	Asteraceae (Daisy Family)
Genus	Ambrosia	Erigeron
Species	Ambrosia hispida	Erigeron philadelphicus

Evolutionary Relationship

Coastal Ragweed and Common Fleabane share a common ancestor at the Family level: Asteraceae. (Daisy Family)

Conservation Status

Coastal Ragweed

LC — Least Concern

Common Fleabane

NE — Not Evaluated

Physical Characteristics

Attribute	Coastal Ragweed	Common Fleabane
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.

Common Fleabane

Habitat

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

Range

Widely distributed across Asia (China, Japan), Europe (8 countries), and North America (United States).

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.

Common Fleabane

<em>Erigeron philadelphicus</em> is an annual or biennial herbaceous plant in the family Asteraceae, order Asterales, commonly known as Philadelphia fleabane or common fleabane. This species produces numerous small, pale pink to white daisy-like flowerheads with many narrow ray florets surrounding a yellow disc center. <em>Erigeron philadelphicus</em> has a broad distribution spanning Asia, Europe, and North America, where it is native and widely naturalized. It typically grows in moist, disturbed habitats such as meadows, roadsides, stream banks, and open woodland, tolerating a wide range of soil types and moisture conditions. The plant is generally considered a common weed in many parts of its range and is notable for its prolific seed production, which facilitates rapid colonization of disturbed ground. Despite its weedy tendencies, the species provides valuable nectar resources for pollinators. Biological traits of this species remain poorly documented in the scientific literature.