closed-sheathed cottongrass vs Common Cotton-Grass

Eriophorum brachyantherum compared with Eriophorum angustifolium

Taxonomic Classification

Rank	closed-sheathed cottongrass	Common Cotton-Grass
Kingdom same	Plantae (พืช)	Plantae (พืช)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Liliopsida (Monocots)	Liliopsida (Monocots)
Order same	Poales (อันดับหญ้า)	Poales (อันดับหญ้า)
Family same	Cyperaceae	Cyperaceae
Genus same	Eriophorum	Eriophorum
Species	Eriophorum brachyantherum	Eriophorum angustifolium

Evolutionary Relationship

closed-sheathed cottongrass and Common Cotton-Grass share a common ancestor at the Genus level: Eriophorum.

Conservation Status

closed-sheathed cottongrass

VU — Vulnerable

Common Cotton-Grass

VU — Vulnerable

Physical Characteristics

Attribute	closed-sheathed cottongrass	Common Cotton-Grass
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

closed-sheathed cottongrass

Habitat

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

Range

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

Common Cotton-Grass

Habitat

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

Range

Found across Europe (6 countries) and North America (United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

closed-sheathed cottongrass

Closed-sheathed cottongrass is a sedge in the genus Eriophorum (family Cyperaceae) characterized by leaf sheaths that are fused to form a closed tube around the stem, a morphological feature distinguishing it from open-sheathed relatives. Cottongrasses are quintessential plants of northern peatlands, bogs, and acidic fens across the boreal and arctic zones of the Northern Hemisphere, producing conspicuous cottony white seed heads — modified perianth bristles elongating as fruits mature — that transform peat bogs into spectacular white-tufted landscapes in late spring and early summer. These plants are ecological keystones of Sphagnum-dominated peat bogs, contributing organic matter through their dense root systems that resist decomposition in waterlogged, oxygen-depleted conditions, driving peat formation over millennia. Eriophorum species serve as important food plants for ptarmigan, geese, and various invertebrates in arctic and subarctic ecosystems. Climate change threatens cottongrass habitats through warmer temperatures accelerating peat decomposition, altered hydrological regimes, and permafrost thaw that fundamentally transforms the structure of northern peatlands.

Common Cotton-Grass

<em>Eriophorum angustifolium</em>, commonly known as common cotton grass or many-stalked cottongrass, is a perennial sedge in the family Cyperaceae. It is distributed across peatlands, bogs, fens, and wet moorlands of Europe and North America, where it is often a dominant and ecologically significant species. Common cotton grass is easily recognized by its distinctive fluffy white seed heads, which resemble balls of cotton and appear conspicuously across boggy landscapes in late spring and summer. These cotton-like structures are modified perianth bristles that aid in wind dispersal of seeds. The species plays a vital role in peatland ecosystems as a peat-forming plant and provides food and nesting material for various wetland birds. It is assessed as Vulnerable on the IUCN Red List, reflecting ongoing habitat loss due to peatland drainage, agricultural conversion, and climate change. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 2 countries:

🇳🇴 Norway 🇸🇪 Sweden