Castor vs Concentric Boulder Lichen

Ricinus communis compared with Porpidia crustulata

Key Differences

Castor is Not Evaluated while Concentric Boulder Lichen is Vulnerable.

Taxonomic Classification

Rank	Castor	Concentric Boulder Lichen
Kingdom	Plantae (식물)	Fungi (균계)
Phylum	Magnoliophyta (피자식물문)	Ascomycota (자낭균류)
Class	Magnoliopsida (목련강)	Lecanoromycetes (요강버섯강)
Order	Malpighiales (말피기아목)	Lecideales (Lecideales)
Family	Euphorbiaceae	Lecideaceae
Genus	Ricinus	Porpidia
Species	Ricinus communis	Porpidia crustulata

Conservation Status

Castor

NE — Not Evaluated

Concentric Boulder Lichen

VU — Vulnerable

Physical Characteristics

Attribute	Castor	Concentric Boulder Lichen
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Castor

Habitat

Found across multiple habitat types including tropical and subtropical dry broadleaf forests, flooded grasslands and savannas, and montane grasslands and shrublands, among 7 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (33 countries), Asia (26 countries), Europe (23 countries), North America (15 countries), Oceania and the Pacific (14 countries), and South America (12 countries).

Concentric Boulder Lichen

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 Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Castor

The Castor (Ricinus communis) is a species in the genus Ricinus. Found across multiple habitat types including tropical and subtropical dry broadleaf forests, flooded grasslands and savannas, and montane grasslands and shrublands, among 7 distinct biome types. Populations are also found in montane and hi

Concentric Boulder Lichen

<em>Porpidia crustulata</em>, commonly known as the Concentric Boulder Lichen, is a crustose lichen in the family Porpidiaceae formed through a symbiotic relationship between a fungal partner (mycobiont) and photosynthetic green algae (photobiont). Like all crustose lichens, it grows tightly appressed to its substrate—typically siliceous or acidic rock surfaces including boulders, cliff faces, and pebbles in open, well-lit habitats—forming thin, grayish to pale thalli marked by scattered black apothecia (reproductive discs). <em>Porpidia crustulata</em> derives nutrition entirely through photosynthesis conducted by its algal partner, requiring no external organic food source. The species has been documented in Denmark, Norway, Portugal, Sweden, and the United States, suggesting a broad boreal to temperate distribution across the Northern Hemisphere. It is currently classified as Vulnerable by the IUCN, indicating significant conservation concern, likely linked to threats including air pollution, acidification, quarrying of rocky habitats, and changes in land use that reduce the availability of suitable substrates. Crustose lichens are typically slow-growing, long-lived organisms with limited capacity for rapid range shifts in response to environmental change. Biological traits such as individual lifespan, growth rates, and reproductive output remain poorly documented at the population level.