Bloodwort vs Common Knotweed

Achillea millefolium compared with Polygonum arenastrum

Key Differences

• Bloodwort is Least Concern while Common Knotweed is Not Evaluated.

Taxonomic Classification

Rank	Bloodwort	Common Knotweed
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class same	Magnoliopsida (Dicots)	Magnoliopsida (Dicots)
Order	Asterales (Daisies & Sunflowers)	Caryophyllales (Caryophyllales)
Family	Asteraceae (Daisy Family)	Polygonaceae
Genus	Achillea	Polygonum
Species	Achillea millefolium	Polygonum arenastrum

Evolutionary Relationship

Bloodwort and Common Knotweed share a common ancestor at the Class level: Magnoliopsida. (Dicots)

Conservation Status

Bloodwort

LC — Least Concern

Common Knotweed

NE — Not Evaluated

Physical Characteristics

Attribute	Bloodwort	Common Knotweed
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Bloodwort

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and flooded grasslands and savannas, among 11 distinct biome types spanning the Indomalayan and Neotropic and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (South Africa), Asia (4 countries), Europe (10 countries), North America (5 countries), Oceania and the Pacific (Australia), and South America (4 countries).

Common Knotweed

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Asia (Taiwan), Europe (10 countries), and North America (Mexico, United States).

Bloodwort

The Bloodwort (Achillea millefolium) is a species in the genus Achillea. It is currently classified as Least Concern on the IUCN Red List. Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and flooded grasslands and savannas, among 11 distinct biome types spanning the Indomalayan and Neotropic and Palearctic real

Common Knotweed

Common Knotweed (<em>Polygonum arenastrum</em>) is a prostrate annual herb in the family Polygonaceae, distributed across Asia, Europe, and North America. Its native range encompasses Taiwan in Asia, ten European countries, and Mexico and the United States in North America. The species typically colonizes highly disturbed, compacted substrates such as footpaths, roadsides, cultivated ground, and waste places, exhibiting a strong association with anthropogenic disturbance. Its wiry, branching stems and small, pale pink flowers form dense mats close to the ground, making it well adapted to trampled environments. The conservation status of this species has not been formally evaluated by the IUCN. As a cosmopolitan ruderal plant, it is broadly tolerant of environmental stress and contributes to ground cover in highly modified habitats throughout the temperate zone. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 7 countries:

🇧🇪 Belgium 🇫🇷 France 🇳🇴 Norway 🇵🇹 Portugal 🇷🇺 Russia 🇹🇼 Taiwan 🇺🇸 United States