Coastal Ragweed vs Common Button Lichen

Ambrosia hispida compared with Buellia erubescens

Key Differences

• Coastal Ragweed is Least Concern while Common Button Lichen is Not Evaluated.

Taxonomic Classification

Rank	Coastal Ragweed	Common Button Lichen
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Ascomycota (Sac Fungi)
Class	Magnoliopsida (Dicots)	Lecanoromycetes (Lecanoromycetes)
Order	Asterales (Daisies & Sunflowers)	Caliciales (Caliciales)
Family	Asteraceae (Daisy Family)	Caliciaceae
Genus	Ambrosia	Buellia
Species	Ambrosia hispida	Buellia erubescens

Conservation Status

Coastal Ragweed

LC — Least Concern

Common Button Lichen

NE — Not Evaluated

Physical Characteristics

Attribute	Coastal Ragweed	Common Button Lichen
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.

Common Button Lichen

Habitat

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

Range

Distributed across Norway, Portugal, Sweden, Taiwan, and United States.

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.

Common Button Lichen

<em>Buellia erubescens</em>, commonly known as the common button lichen, is a lichen species with documented occurrences across Asia, Europe, and North America, including countries such as Norway, Portugal, Sweden, Taiwan, and the United States. It typically colonizes diverse terrestrial surfaces, often found on bark, rock, or other substrates in temperate and boreal environments. Common button lichen belongs to the genus <em>Buellia</em> within the family Caliciaceae. As a crustose lichen, it typically forms tightly adhered, crust-like thalli on the surfaces it colonizes, making it characteristic of stable, undisturbed substrates. Biological traits such as average lifespan, thallus size, and biomass of this species remain poorly documented in the scientific literature. The species has not yet been formally evaluated by the IUCN, and its global conservation status therefore remains undetermined. Its occurrence across multiple continents suggests a wide ecological tolerance, though detailed population data and trend assessments are currently lacking for this taxon.