Common Stonewort vs small tortoiseshell

Chara vulgaris compared with Aglais urticae

Key Differences

• Common Stonewort is Endangered while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	Common Stonewort	small tortoiseshell
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Charophyta (Charophyta)	Arthropoda (Arthropods)
Class	Charophyceae (Charophyceae)	Insecta (Insects)
Order	Charales (Charales)	Lepidoptera (Butterflies & Moths)
Family	Characeae	Nymphalidae (Brush-footed Butterflies)
Genus	Chara	Aglais
Species	Chara vulgaris	Aglais urticae

Conservation Status

Common Stonewort

EN — Endangered

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	Common Stonewort	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Stonewort

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (Denmark, Norway, Sweden), North America (United States), and South America (Brazil). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Common Stonewort

<em>Chara vulgaris</em>, the common stonewort, is a species of charophyte green alga in the family Characeae, order Charales. It typically grows submerged in freshwater habitats including ponds, lakes, ditches, and slow-moving streams, often forming dense mats on the substrate. The species has a broad geographic distribution spanning Asia, Europe, and the Americas, tolerating a range of water conditions from clear to moderately turbid. <em>Chara vulgaris</em> is notable for its heavily calcified, whorled structure that gives stoneworts their characteristic encrusted appearance and makes them valuable as paleoclimate indicators in sediment records. As a primary producer, it contributes to aquatic food webs and provides habitat for invertebrates and juvenile fish. Biological traits such as individual lifespan, precise growth rates, and specific consumer relationships remain poorly documented in the literature. Despite its wide range, <em>Chara vulgaris</em> is assessed as Endangered by the IUCN, reflecting significant population declines attributed to freshwater pollution, eutrophication, and habitat degradation across much of its range. Targeted conservation of clean, oligotrophic water bodies is essential for its persistence.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden