Coastal Ragweed vs Collared Earthstar

Ambrosia hispida compared with Geastrum triplex

Key Differences

• Coastal Ragweed is Least Concern while Collared Earthstar is Near Threatened.

Taxonomic Classification

Rank	Coastal Ragweed	Collared Earthstar
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Basidiomycota (Club Fungi)
Class	Magnoliopsida (Dicots)	Agaricomycetes (Mushrooms)
Order	Asterales (Daisies & Sunflowers)	Geastrales (Geastrales)
Family	Asteraceae (Daisy Family)	Geastraceae
Genus	Ambrosia	Geastrum
Species	Ambrosia hispida	Geastrum triplex

Conservation Status

Coastal Ragweed

LC — Least Concern

Collared Earthstar

NT — Near Threatened

Physical Characteristics

Attribute	Coastal Ragweed	Collared Earthstar
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.

Collared Earthstar

Habitat

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

Range

Distributed across Belgium, Brazil, Norway, and United States. 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.

Collared Earthstar

<em>Geastrum triplex</em>, the Collared Earthstar, is a gasteroid fungus in the family Geastraceae, order Geastrales. This species is assessed as Near Threatened on the IUCN Red List, indicating that it may be at risk of qualifying for a threatened category in the near future. It has been recorded in Belgium, Brazil, Norway, and the United States, and is associated with forest floors, decomposing wood, and soil. Earthstars in the genus <em>Geastrum</em> are recognized by their distinctive star-shaped fruiting bodies, formed when the outer wall splits and folds back into ray-like segments to reveal an inner spore sac. <em>Geastrum triplex</em> is distinguished by the formation of a collar or cup-like structure around the base of the inner spore sac, which gives rise to its common name. Like other gasteroid fungi, it disperses spores through an apical pore in the spore sac. Population estimates and trend data are not available. Biological traits of this species remain poorly documented in the scientific literature. Its Near Threatened status may reflect sensitivity to habitat disturbance and forest management practices.