Black Stubble Lichen vs Clusterspike False Indigo

Calicium abietinum compared with Amorpha crenulata

Key Differences

• Black Stubble Lichen is Endangered while Clusterspike False Indigo is Critically Endangered.

Taxonomic Classification

Rank	Black Stubble Lichen	Clusterspike False Indigo
Kingdom	Fungi (Fungi)	Plantae (Plants)
Phylum	Ascomycota (Sac Fungi)	Magnoliophyta (Flowering Plants)
Class	Lecanoromycetes (Lecanoromycetes)	Magnoliopsida (Dicots)
Order	Caliciales (Caliciales)	Fabales (Legumes & Allies)
Family	Caliciaceae	Fabaceae
Genus	Calicium	Amorpha
Species	Calicium abietinum	Amorpha crenulata

Conservation Status

Black Stubble Lichen

EN — Endangered

Clusterspike False Indigo

CR — Critically Endangered

Physical Characteristics

Attribute	Black Stubble Lichen	Clusterspike False Indigo
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black Stubble Lichen

Habitat

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

Range

Widely distributed across Europe (4 countries), North America (United States), and South America (Colombia). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Clusterspike False Indigo

Habitat

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

Black Stubble Lichen

The Black Stubble Lichen (Calicium abietinum) is a species in the genus Calicium. It is currently classified as Endangered on the IUCN Red List. Native to Europe and North America and South America, inhabiting ecosystems characteristic of the region, found across Colombia, Denmark, Norway, Portugal, Sweden, and more.

Clusterspike False Indigo

Amorpha crenulata, known as clusterspike false indigo or crenulate lead plant, is a critically endangered flowering shrub in the family Fabaceae with a highly restricted distribution confined to Miami-Dade County in southern Florida, USA. This species represents one of North America's rarest plants, with remaining populations numbering in the hundreds of individuals occurring in pine rockland habitat, an ecosystem itself ranked among the most imperiled in the United States. Pine rocklands are fire-dependent communities on exposed oolitic limestone, characterized by an open canopy of slash pine over diverse understory, and have been reduced to less than two percent of their historical extent by urban development in the Miami metropolitan area. Amorpha crenulata produces elongated spikes of small purple flowers typical of the genus and was historically more widespread across the Miami Rock Ridge before land development eliminated most habitat. Current populations exist primarily within Everglades National Park and a few private preserves. Its Critically Endangered status reflects the tiny remaining population, extreme habitat restriction, ongoing threats from urbanization, altered fire regimes, and sea-level rise that threatens low-elevation limestone habitats. Conservation efforts focus on habitat protection, controlled burning to maintain pine rockland structure, and ex situ seed banking.