Clusterspike False Indigo vs Common Stump Brittlestem

Amorpha crenulata compared with Psathyrella piluliformis

Key Differences

• Clusterspike False Indigo is Critically Endangered while Common Stump Brittlestem is Least Concern.

Taxonomic Classification

Rank	Clusterspike False Indigo	Common Stump Brittlestem
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Basidiomycota (Club Fungi)
Class	Magnoliopsida (Dicots)	Agaricomycetes (Mushrooms)
Order	Fabales (Legumes & Allies)	Agaricales (Gilled Mushrooms)
Family	Fabaceae	Psathyrellaceae
Genus	Amorpha	Psathyrella
Species	Amorpha crenulata	Psathyrella piluliformis

Conservation Status

Clusterspike False Indigo

CR — Critically Endangered

Common Stump Brittlestem

LC — Least Concern

Physical Characteristics

Attribute	Clusterspike False Indigo	Common Stump Brittlestem
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clusterspike False Indigo

Habitat

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

Common Stump Brittlestem

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), North America (United States), and South America (Brazil).

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.

Common Stump Brittlestem

<em>Psathyrella piluliformis</em>, the common stump brittlestem, is a saprotrophic basidiomycete fungus in the family Psathyrellaceae, order Agaricales. It has a broad distribution across Asia, Europe, and the Americas, typically found growing in dense clusters on or near the stumps and buried roots of deciduous trees, particularly oaks and beeches, from autumn through to early winter. The fruitbodies are hygrophanous, changing colour dramatically depending on moisture content, ranging from pale buff when dry to a rich honey-brown when wet. <em>Psathyrella piluliformis</em> plays an important ecological role as a wood decomposer, facilitating the breakdown of lignin and cellulose and contributing to nutrient cycling in forest ecosystems. The fragile, brittle gills and thin-walled spores are characteristic of the genus. Biological traits including average mycelial lifespan, fruiting body dimensions under natural conditions, and specific substrate preferences remain poorly documented. The species is assessed as Least Concern by the IUCN, reflecting its wide distribution and apparent abundance across temperate woodland habitats in the Northern Hemisphere and beyond.