Autumn Snowflake vs Common Tarcrust

Acis autumnalis compared with Diatrype stigma

Key Differences

Autumn Snowflake is Least Concern while Common Tarcrust is Not Evaluated.

Taxonomic Classification

Rank	Autumn Snowflake	Common Tarcrust
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Ascomycota (Sac Fungi)
Class	Liliopsida (Monocots)	Sordariomycetes (Sordariomycetes)
Order	Asparagales (Asparagales)	Xylariales (Xylariales)
Family	Amaryllidaceae	Diatrypaceae
Genus	Acis	Diatrype
Species	Acis autumnalis	Diatrype stigma

Conservation Status

Autumn Snowflake

LC — Least Concern

Common Tarcrust

NE — Not Evaluated

Physical Characteristics

Attribute	Autumn Snowflake	Common Tarcrust
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Autumn Snowflake

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Range

Found in Norway.

Common Tarcrust

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Belgium, Denmark, Norway, Portugal, and Sweden.

Autumn Snowflake

The Autumn Snowflake (Acis autumnalis) is a species in the genus Acis. It is currently classified as Least Concern on the IUCN Red List. Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Common Tarcrust

<em>Diatrype stigma</em>, the common tarcrust, is a saprotrophic fungus in the family Diatrypaceae, found across Belgium, Denmark, Norway, Portugal, and Sweden, as well as more broadly in Europe and temperate regions globally. It grows as a crust-like, charcoal-black stromata on the dead bark and branches of deciduous hardwoods, particularly hazel, beech, and alder. The fruiting bodies are typically flat to slightly raised, dark gray to black patches that contain numerous embedded perithecia in which ascospores are produced. This fungus plays an important ecological role as a decomposer, breaking down dead woody material and recycling nutrients in forest ecosystems. It is Not Evaluated on the IUCN Red List; given its broad distribution on common substrates, it is generally considered widespread. The species reproduces via wind-dispersed ascospores released from the perithecia. Diet, as a saprotrophic organism, consists of dead organic woody matter. Biological traits such as colony growth rates, spore output, and longevity remain poorly documented in standardized quantitative assessments.