Clint Crisp-Moss vs Coastal Ragweed

Tortella densa compared with Ambrosia hispida

Taxonomic Classification

Rank	Clint Crisp-Moss	Coastal Ragweed
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum	Bryophyta	Magnoliophyta (Flowering Plants)
Class	Bryopsida (Bryopsida)	Magnoliopsida (Dicots)
Order	Pottiales (Pottiales)	Asterales (Daisies & Sunflowers)
Family	Pottiaceae	Asteraceae (Daisy Family)
Genus	Tortella	Ambrosia
Species	Tortella densa	Ambrosia hispida

Evolutionary Relationship

Clint Crisp-Moss and Coastal Ragweed share a common ancestor at the Kingdom level: Plantae. (Plants)

Conservation Status

Clint Crisp-Moss

LC — Least Concern

Coastal Ragweed

LC — Least Concern

Physical Characteristics

Attribute	Clint Crisp-Moss	Coastal Ragweed
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clint Crisp-Moss

Habitat

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

Range

Distributed across Norway, Sweden, and United States.

Coastal Ragweed

Habitat

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

Range

Found in Cuba.

Clint Crisp-Moss

Clint Crisp-moss, Tortella densa, is a small acrocarpous moss in the family Pottiaceae found on exposed limestone pavement, cliff ledges, and calcareous rock outcrops in temperate Europe, with strongholds in the Yorkshire Dales, the Burren of Ireland, and similar karst landscapes. The common name 'clint' refers to the raised limestone blocks of limestone pavement habitats, and 'crisp-moss' describes the crinkled, crisped appearance of the dry leaf margins. When moistened, the leaves uncurl and spread, revealing the characteristic nerve extending to the leaf tip. Tortella densa forms dense, cushion-like or turf-forming colonies on exposed limestone surfaces and in sheltered grykes (the fissures between clints), tolerating periodic desiccation and temperature extremes. Limestone pavement is a rare and highly specialized habitat that supports a distinctive community of plants, mosses, liverworts, and invertebrates, and is legally protected in the United Kingdom and Ireland as a priority habitat under European conservation law. The loss of limestone pavement to quarrying, the covering of surfaces by soil and vegetation succession, and the removal of clint-surface plants by collectors have threatened specialist bryophytes of this habitat. Clint Crisp-moss is considered of conservation concern in Britain and Ireland.

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.