Clustered Stonewort vs Great Reed Warbler

Tolypella glomerata compared with Acrocephalus arundinaceus

Key Differences

Clustered Stonewort is Vulnerable while Great Reed Warbler is Critically Endangered.

Taxonomic Classification

Rank	Clustered Stonewort	Great Reed Warbler
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Charophyta (Charophyta)	Chordata (Chordates)
Class	Charophyceae (Charophyceae)	Aves (Birds)
Order	Charales (Charales)	Passeriformes (Songbirds)
Family	Characeae	Acrocephalidae
Genus	Tolypella	Acrocephalus
Species	Tolypella glomerata	Acrocephalus arundinaceus

Conservation Status

Clustered Stonewort

VU — Vulnerable

Great Reed Warbler

CR — Critically Endangered

Physical Characteristics

Attribute	Clustered Stonewort	Great Reed Warbler
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clustered Stonewort

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

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

Great Reed Warbler

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

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

Clustered Stonewort

Tolypella glomerata, the clustered stonewort, is a charophyte alga in the family Characeae, found in calcareous, nutrient-poor freshwater habitats including lakes, ponds, ditches, and slow-flowing water in northwestern and northern Europe. Charophytes are macroscopic green algae with a distinctive whorl-like arrangement of branches and a complex, plant-like structure that distinguishes them from other algae. T. glomerata is encrusted with calcium carbonate deposits (hence 'stonewort'), giving it a pale, grey-green appearance and rough texture. The species colonizes clear, low-nutrient water over fine sediment or gravel substrates where competition from vascular plants is reduced by nutrient limitation. It is listed as Vulnerable by the IUCN, reflecting significant declines driven by eutrophication (nutrient enrichment from agriculture and sewage), which promotes the growth of vascular plants and phytoplankton that shade out stoneworts. Drainage, water abstraction, and peat cutting also threaten its habitats. Charophyte diversity has declined substantially across lowland Europe and North America over the past century, with many species becoming locally extinct from sites they once colonized.

Great Reed Warbler

Great Reed Warbler (Acrocephalus arundinaceus) is classified as Critically Endangered (CR) on the IUCN Red List. Facing an extremely high risk of extinction in the wild due to severe population decline and habitat loss.