Coastal Ragweed vs Large-flowered Hemp-nettle

Ambrosia hispida compared with Galeopsis speciosa

Key Differences

• Coastal Ragweed is Least Concern while Large-flowered Hemp-nettle is Near Threatened.

Taxonomic Classification

Rank	Coastal Ragweed	Large-flowered Hemp-nettle
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Magnoliopsida (Dicots)	Magnoliopsida (Dicots)
Order	Asterales (Daisies & Sunflowers)	Lamiales (Lamiales)
Family	Asteraceae (Daisy Family)	Lamiaceae
Genus	Ambrosia	Galeopsis
Species	Ambrosia hispida	Galeopsis speciosa

Evolutionary Relationship

Coastal Ragweed and Large-flowered Hemp-nettle share a common ancestor at the Class level: Magnoliopsida. (Dicots)

Conservation Status

Coastal Ragweed

LC — Least Concern

Large-flowered Hemp-nettle

NT — Near Threatened

Physical Characteristics

Attribute	Coastal Ragweed	Large-flowered Hemp-nettle
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.

Large-flowered Hemp-nettle

Habitat

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

Range

Found across Europe (11 countries) and North America (Canada). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

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.