Common Duckweed vs Polar bear

Lemna minor compared with Ursus maritimus

Key Differences

Common Duckweed is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Common Duckweed	Polar bear
Kingdom	Plantae (植物)	Animalia (動物)
Phylum	Magnoliophyta (被子植物門)	Chordata (脊索動物)
Class	Liliopsida (単子葉植物綱)	Mammalia (哺乳類)
Order	Alismatales (オモダカ目)	Carnivora (ネコ目)
Family	Araceae	Ursidae (Bears)
Genus	Lemna	Ursus (Bears)
Species	Lemna minor	Ursus maritimus

Conservation Status

Common Duckweed

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Duckweed	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Common Duckweed

Habitat

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

Range

Widely distributed across Europe (8 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (Brazil, Guyana).

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Duckweed

<em>Lemna minor</em>, commonly known as common duckweed, is a tiny floating aquatic plant in the family Araceae, recognized as one of the smallest flowering plants on Earth. Classified as Least Concern by the IUCN, the species enjoys a broad distribution across Europe, North America, Oceania, and South America, colonizing a diverse array of habitats including grasslands, wetlands, forests, and cultivated land with access to standing or slow-moving water. It typically inhabits ponds, lakes, ditches, and quiet streams, forming extensive green mats on the water surface. <em>Lemna minor</em> reproduces predominantly through asexual budding, allowing populations to expand rapidly under favorable conditions. The species provides vital ecosystem services, stabilizing nutrient cycles, reducing algal blooms through competition, and offering food and shelter for aquatic invertebrates, fish, and waterfowl. Due to its sensitivity to water quality, it is frequently used as a bioindicator in ecotoxicological research. Common duckweed has also attracted scientific interest for its potential in wastewater treatment and as a high-protein animal feed supplement. Biological traits of this species remain poorly documented in the scientific literature.

Polar bear

地球上で最大の陸上肉食動物であるホッキョクグマは700kgを超えることがあり、カナダからロシアまでの北極海氷域全体に分布する。ワモンアザラシとヒゲアザラシを狩るために海氷に依存する高度に特化した海洋哺乳類である。広大な距離を泳ぐことができる優れた泳者でもある。脆弱種に指定されており、気候変動による急激な北極海氷の消失で個体群が深刻な圧力を受けている。