Compact Stonewort vs Dark Stonewort

Nitella mucronata compared with Nitella opaca

Key Differences

• Compact Stonewort is Vulnerable while Dark Stonewort is Least Concern.

Taxonomic Classification

Rank	Compact Stonewort	Dark Stonewort
Kingdom same	Plantae (พืช)	Plantae (พืช)
Phylum same	Charophyta (Charophyta)	Charophyta (Charophyta)
Class same	Charophyceae (Charophyceae)	Charophyceae (Charophyceae)
Order same	Charales (Charales)	Charales (Charales)
Family same	Characeae	Characeae
Genus same	Nitella	Nitella
Species	Nitella mucronata	Nitella opaca

Evolutionary Relationship

Compact Stonewort and Dark Stonewort share a common ancestor at the Genus level: Nitella.

Conservation Status

Compact Stonewort

VU — Vulnerable

Dark Stonewort

LC — Least Concern

Physical Characteristics

Attribute	Compact Stonewort	Dark Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic 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.

Dark Stonewort

Habitat

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

Range

Distributed across Brazil, Denmark, Norway, Sweden, and United States.

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 5 countries:

🇧🇷 Brazil 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States