Coastal Ragweed vs

Ambrosia hispida compared with Pyrenula nitida

Key Differences

Coastal Ragweed is Least Concern while is Endangered.

Taxonomic Classification

Rank	Coastal Ragweed
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Ascomycota (Sac Fungi)
Class	Magnoliopsida (Dicots)	Eurotiomycetes (Eurotiomycetes)
Order	Asterales (Daisies & Sunflowers)	Pyrenulales (Pyrenulales)
Family	Asteraceae (Daisy Family)	Pyrenulaceae
Genus	Ambrosia	Pyrenula
Species	Ambrosia hispida	Pyrenula nitida

Conservation Status

Coastal Ragweed

LC — Least Concern

EN — Endangered

Physical Characteristics

Attribute	Coastal Ragweed
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.

Habitat

Native to Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, Portugal, Sweden, and United States. Currently classified as 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.

Pyrenula nitida is a corticolous crustose lichen producing a smooth, glossy olive-green to brown thallus with embedded, flask-shaped perithecia on smooth bark of ancient broadleaf trees in humid Atlantic woodland. It is considered a flagship indicator species for long-continuity, old-growth woodland in western Europe. Endangered, this lichen is severely threatened by the loss of veteran trees and ancient woodland habitats.