Andersson's arctic moss vs Compact Stonewort

Arctoa anderssonii compared with Nitella mucronata

Key Differences

• Andersson's arctic moss is Endangered while Compact Stonewort is Vulnerable.

Taxonomic Classification

Rank	Andersson's arctic moss	Compact Stonewort
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum	Bryophyta	Charophyta (Charophyta)
Class	Bryopsida (Bryopsida)	Charophyceae (Charophyceae)
Order	Dicranales (Dicranales)	Charales (Charales)
Family	Rhabdoweisiaceae	Characeae
Genus	Arctoa	Nitella
Species	Arctoa anderssonii	Nitella mucronata

Evolutionary Relationship

Andersson's arctic moss and Compact Stonewort share a common ancestor at the Kingdom level: Plantae. (Plants)

Conservation Status

Andersson's arctic moss

EN — Endangered

Compact Stonewort

VU — Vulnerable

Physical Characteristics

Attribute	Andersson's arctic moss	Compact Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Andersson's arctic moss

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Compact Stonewort

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 (Brazil). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Andersson's arctic moss

The Andersson's arctic moss (Arctoa anderssonii) is a species in the genus Arctoa. It is currently classified as Endangered on the IUCN Red List. Native to Europe, inhabiting ecosystems characteristic of the region.

Compact Stonewort

<em>Nitella mucronata</em>, compact stonewort, is a freshwater macroalga in the family Characeae, belonging to the charophyte lineage considered the closest algal relatives of land plants. It has been recorded from fresh and brackish water bodies in Belgium, Brazil, Denmark, Norway, Sweden, and the United States, inhabiting clear, nutrient-poor lakes, ponds, and slow-moving streams. Stoneworts of the genus Nitella are delicate, translucent plants lacking the calcium carbonate encrustation typical of the related genus Chara, growing submerged in well-lit, oligotrophic aquatic environments. They typically form dense underwater meadows that provide important habitat for invertebrates and small fish, while also stabilising sediments and contributing to water clarity through nutrient uptake. <em>Nitella mucronata</em> is classified as Vulnerable by the IUCN, reflecting sensitivity to water quality deterioration, eutrophication from agricultural runoff and sewage, and the loss of clear, unpolluted water bodies across its range in Europe and beyond. The species is particularly vulnerable to increased phosphorus and nitrogen loading, which promotes algal blooms that shade out submerged macrophytes. Biological traits including average lifespan, reproduction rates, and morphological measurements remain poorly documented compared to more widespread charophyte species. Conservation of <em>Nitella mucronata</em> depends on improving water quality in its freshwater habitats and protecting oligotrophic water bodies from nutrient pollution.

Shared Countries

Both species can be found in 2 countries:

🇳🇴 Norway 🇸🇪 Sweden