Columbia Water-Meal vs Rootless Duckweed

Wolffia columbiana compared with Wolffia arrhiza

Key Differences

• Columbia Water-Meal is Least Concern while Rootless Duckweed is Endangered.

Taxonomic Classification

Rank	Columbia Water-Meal	Rootless Duckweed
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Liliopsida (Monocots)	Liliopsida (Monocots)
Order same	Alismatales (Alismatales)	Alismatales (Alismatales)
Family same	Araceae	Araceae
Genus same	Wolffia	Wolffia
Species	Wolffia columbiana	Wolffia arrhiza

Evolutionary Relationship

Columbia Water-Meal and Rootless Duckweed share a common ancestor at the Genus level: Wolffia.

Conservation Status

Columbia Water-Meal

LC — Least Concern

Rootless Duckweed

EN — Endangered

Physical Characteristics

Attribute	Columbia Water-Meal	Rootless Duckweed
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Columbia Water-Meal

Habitat

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

Range

Widely distributed across Asia (India), Europe (4 countries), North America (Canada, United States), and South America (Brazil, Colombia).

Rootless Duckweed

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and temperate coniferous forests, among 4 distinct biome types spanning the Indomalayan and Oceanian and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Japan), Europe (10 countries), North America (Canada), and South America (Brazil). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Columbia Water-Meal

<em>Wolffia columbiana</em> is a diminutive aquatic flowering plant belonging to the family Araceae, widely recognized as one of the smallest known vascular plants on Earth. It inhabits still or slow-moving freshwater environments, including ponds, lakes, ditches, and quiet backwaters, where it floats freely at or just below the water surface. The species occurs across a broad geographic range spanning the Americas. As a rootless, leafless organism, <em>W. columbiana</em> consists of a tiny oval thallus, measuring only a fraction of a millimeter in diameter, which carries out photosynthesis directly through its green surface tissue. Reproduction is primarily vegetative, with daughter plants budding from a specialized pouch on the parent thallus, enabling rapid population expansion under favorable conditions. The species is assessed as Least Concern on the IUCN Red List, reflecting its wide distribution and tolerance of varied freshwater conditions.

Shared Countries

Both species can be found in 5 countries:

🇧🇪 Belgium 🇧🇷 Brazil 🇨🇦 Canada 🇮🇹 Italy 🇸🇪 Sweden