Coastal Ragweed vs Compact brome

Ambrosia hispida compared with Bromus madritensis

Key Differences

• Coastal Ragweed is Least Concern while Compact brome is Not Evaluated.

Taxonomic Classification

Rank	Coastal Ragweed	Compact brome
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class	Magnoliopsida (Dicots)	Liliopsida (Monocots)
Order	Asterales (Daisies & Sunflowers)	Poales (Grasses)
Family	Asteraceae (Daisy Family)	Poaceae (Grass Family)
Genus	Ambrosia	Bromus
Species	Ambrosia hispida	Bromus madritensis

Evolutionary Relationship

Coastal Ragweed and Compact brome share a common ancestor at the Phylum level: Magnoliophyta. (Flowering Plants)

Conservation Status

Coastal Ragweed

LC — Least Concern

Compact brome

NE — Not Evaluated

Physical Characteristics

Attribute	Coastal Ragweed	Compact brome
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.

Compact brome

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Range

Widely distributed across Africa (South Africa), Asia (Japan), Europe (15 countries), North America (Mexico, United States), Oceania and the Pacific (Australia), and South America (Chile).

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.

Compact brome

<em>Bromus madritensis</em>, compact brome or Madrid brome, is an annual grass in the family Poaceae with an expansive native distribution across the Mediterranean basin, extending into parts of Africa, the Middle East, and central Asia. It has also been widely introduced to North America, South America, Australia, and other regions, where it is often considered an invasive weed in disturbed grasslands and shrublands. The species grows typically to 15–50 centimetres in height, producing dense, compact panicles with characteristic bristle-tipped spikelets that aid seed dispersal by attachment to passing animals and clothing. It thrives in dry, disturbed habitats including roadsides, agricultural margins, coastal scrub, and degraded grasslands, demonstrating strong tolerance for poor soils and seasonal drought. Compact brome is a pioneer species that colonises bare ground rapidly and can outcompete native herbaceous vegetation in fragile ecosystems, particularly in California chaparral and Mediterranean-climate shrublands. It is Not Evaluated on the IUCN Red List, consistent with its abundance and broad distribution. The species completes its life cycle entirely within a single growing season, germinating in autumn or winter and setting seed by late spring. Biological traits including precise lifespan data are inherent to its annual habit, but additional morphological and population data remain variable across its wide geographic range.