vs Common Silver Hairgrass

Chroococcus macrococcus compared with Aira caryophyllea

Key Differences

is Not Evaluated while Common Silver Hairgrass is Endangered.

Taxonomic Classification

Rank		Common Silver Hairgrass
Kingdom	Bacteria (Bacteria)	Plantae (Plants)
Phylum	Cyanobacteria (Cyanobacteria)	Magnoliophyta (Flowering Plants)
Class	Cyanobacteriia	Liliopsida (Monocots)
Order	Cyanobacteriales	Poales (Grasses)
Family	Microcystaceae	Poaceae (Grass Family)
Genus	Chroococcus	Aira
Species	Chroococcus macrococcus	Aira caryophyllea

Conservation Status

NE — Not Evaluated

Common Silver Hairgrass

EN — Endangered

Physical Characteristics

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

Habitat & Geographic Range

Habitat

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

Range

Distributed across Norway, Sweden, and United States.

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.

Chroococcus macrococcus is a cyanobacterium in the family Chroococcaceae, belonging to a group of unicellular to loosely colonial coccoid cyanobacteria distributed in freshwater and moist terrestrial environments. The specific epithet macrococcus refers to the large size of the cells, distinguishing this species from smaller-celled members of the genus. Chroococcus cells are characterized by their spherical shape, division by binary fission into pairs or tetrad arrangements, and enclosure within distinct gelatinous sheaths. The outer sheath layers are often visibly stratified in older colonies. Cyanobacteria of the Chroococcaceae occupy a broad range of aquatic and semi-aquatic habitats worldwide, from standing and flowing freshwaters to damp soil, rocks, tree bark, and the surfaces of other organisms. They are among the most ecologically resilient of photosynthetic microorganisms, tolerating desiccation, temperature extremes, and nutrient-poor conditions. Chroococcus macrococcus has been recorded from European freshwater localities. Its ecological significance lies primarily in contributing to primary production in aquatic communities. Like most microorganisms, it has not been formally assessed under IUCN criteria.

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.