American Eelgrass vs Common Silver Hairgrass

Vallisneria americana compared with Aira caryophyllea

Key Differences

• American Eelgrass is Least Concern while Common Silver Hairgrass is Endangered.

Taxonomic Classification

Rank	American Eelgrass	Common Silver Hairgrass
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Liliopsida (Monocots)	Liliopsida (Monocots)
Order	Alismatales (Alismatales)	Poales (Grasses)
Family	Hydrocharitaceae	Poaceae (Grass Family)
Genus	Vallisneria	Aira
Species	Vallisneria americana	Aira caryophyllea

Evolutionary Relationship

American Eelgrass and Common Silver Hairgrass share a common ancestor at the Class level: Liliopsida. (Monocots)

Conservation Status

American Eelgrass

LC — Least Concern

Common Silver Hairgrass

EN — Endangered

Physical Characteristics

Attribute	American Eelgrass	Common Silver Hairgrass
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

American Eelgrass

Habitat

Found across multiple habitat types including deserts and xeric shrublands, tropical and subtropical moist broadleaf forests, and tropical and subtropical grasslands and savannas, among 4 distinct biome types spanning the Palearctic and Neotropic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Egypt), Asia (Taiwan), Europe (Belgium, Italy), North America (5 countries), and South America (Colombia).

Common Silver Hairgrass

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical grasslands and savannas, and flooded grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Cameroon), Asia (Japan, South Korea), Europe (6 countries), North America (4 countries), Oceania and the Pacific (Australia), and South America (4 countries). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

American Eelgrass

The American Eelgrass (Vallisneria americana) is a species in the genus Vallisneria. It is currently classified as Least Concern on the IUCN Red List. Found across multiple habitat types including deserts and xeric shrublands, tropical and subtropical moist broadleaf forests, and tropical and subtropical grasslands and savannas, among 4 distinct biome types spanning the Palearctic and Neo.

Common Silver Hairgrass

<em>Aira caryophyllea</em>, commonly known as Common Silver Hairgrass, is a slender annual grass belonging to the family Poaceae within the order Poales. This delicate grass is currently classified as Endangered on the IUCN Red List, reflecting significant conservation concern despite its historically broad distribution. It is typically found across a remarkable diversity of biome types, including tropical and subtropical moist broadleaf forests, grasslands, savannas, and flooded habitats, demonstrating notable ecological versatility. Its geographic range spans multiple continents, with documented populations in Africa (Cameroon), Asia (Japan, South Korea), Europe, North America, Australia, and South America. As an annual grass, it completes its life cycle within a single growing season, reproducing via wind-dispersed seeds. The inflorescence typically bears silvery, shimmering spikelets that give the species its common name. Biological traits such as average lifespan, body dimensions, and dietary specifics follow typical patterns for annual grasses — drawing nutrients from soil through root absorption rather than consuming other organisms. The endangered status suggests populations may be declining due to habitat loss, land-use change, or invasive species pressure across parts of its range.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇨🇦 Canada 🇨🇴 Colombia 🇺🇸 United States