Coastal Ragweed vs Great Hammerhead

Ambrosia hispida compared with Sphyrna mokarran

Key Differences

• Coastal Ragweed is Least Concern while Great Hammerhead is Critically Endangered.

Taxonomic Classification

Rank	Coastal Ragweed	Great Hammerhead
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Chordata (Chordates)
Class	Magnoliopsida (Dicots)	Chondrichthyes (Cartilaginous Fish)
Order	Asterales (Daisies & Sunflowers)	Carcharhiniformes (Ground Sharks)
Family	Asteraceae (Daisy Family)	Sphyrnidae (Hammerhead Sharks)
Genus	Ambrosia	Sphyrna (Hammerhead Sharks)
Species	Ambrosia hispida	Sphyrna mokarran

Conservation Status

Coastal Ragweed

LC — Least Concern

Great Hammerhead

CR — Critically Endangered

Trend: Decreasing ↓

Physical Characteristics

Attribute	Coastal Ragweed	Great Hammerhead
Diet	—	Carnivore
Average Lifespan	—	40 years
Average Length	—	5.0 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Coastal Ragweed

Habitat

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

Range

Found in Cuba.

Great Hammerhead

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and flooded grasslands and savannas, among 5 distinct biome types spanning the Indomalayan and Neotropic and Oceanian realms. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Colombia, Taiwan, and Venezuela. Currently classified as Critically Endangered 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.

Great Hammerhead

The largest hammerhead shark species, great hammerheads reach up to 6 meters and are found in tropical and subtropical coastal waters worldwide. Their distinctive T-shaped head (cephalofoil) dramatically increases sensory surface area for electroreception, enabling them to detect buried stingrays through sand with exceptional precision — stingrays are a preferred prey. Critically Endangered, with populations declining dramatically due to highly valued fins and bycatch mortality.