Common knotweed vs Scarlet Macaw

Polygonum plebeium compared with Ara macao

Key Differences

Common knotweed is Not Evaluated while Scarlet Macaw is Least Concern.

Taxonomic Classification

Rank	Common knotweed	Scarlet Macaw
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Chordata (Chordates)
Class	Magnoliopsida (Dicots)	Aves (Birds)
Order	Caryophyllales (Caryophyllales)	Psittaciformes (Parrots)
Family	Polygonaceae	Psittacidae (True Parrots)
Genus	Polygonum	Ara (Macaws)
Species	Polygonum plebeium	Ara macao

Conservation Status

Common knotweed

NE — Not Evaluated

Scarlet Macaw

LC — Least Concern

Population: ~50.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common knotweed	Scarlet Macaw
Diet	—	Herbivore
Average Lifespan	—	50 years
Average Length	—	85 cm
Average Weight	—	1.0 kg

Habitat & Geographic Range

Common knotweed

Habitat

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

Range

Widely distributed across Africa (Madagascar), Asia (Japan, Taiwan), Europe (5 countries), and North America (United States).

Scarlet Macaw

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Found across Europe (5 countries) and South America (Colombia, Ecuador, Venezuela). Population trends indicate a declining trajectory in parts of its range.

Common knotweed

Common Knotweed (<em>Polygonum plebeium</em>) is a low-growing annual herb in the family Polygonaceae, widely distributed across Africa, Asia, Europe, and North America. Its native range includes Madagascar in Africa, Japan and Taiwan in Asia, five European countries, and the United States in North America. The species typically inhabits diverse terrestrial environments including roadsides, cultivated fields, waste ground, and disturbed habitats, often thriving in compacted or trampled soils. It is a small, mat-forming plant with tiny pink or white flowers and narrow leaves, well adapted to anthropogenic landscapes. Its conservation status has not been formally evaluated by the IUCN. The broad distributional range and generalist habitat preferences of this species suggest resilience to moderate levels of disturbance, though its ecological role in native plant communities is less well characterized compared to its weedy occurrences in disturbed sites. Biological traits of this species remain poorly documented in the scientific literature.

Scarlet Macaw

One of the most brilliantly colored birds in the Americas, scarlet macaws display vivid red, yellow, and blue plumage with wingspans reaching 1 meter. Found in humid lowland forests from Mexico to Bolivia, they are highly intelligent, long-lived — up to 75 years — and form lifelong pair bonds. They travel long distances to clay licks where they consume mineral-rich soil to detoxify seeds. Listed as Least Concern but locally threatened by habitat loss and the pet trade.