Common Tansy vs Common Water Rat

Tanacetum vulgare compared with Hydromys chrysogaster

Taxonomic Classification

Rank	Common Tansy	Common Water Rat
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Chordata (Chordates)
Class	Magnoliopsida (Dicots)	Mammalia (Mammals)
Order	Asterales (Daisies & Sunflowers)	Rodentia (Rodents)
Family	Asteraceae (Daisy Family)	Muridae (Mice & Rats)
Genus	Tanacetum	Hydromys
Species	Tanacetum vulgare	Hydromys chrysogaster

Conservation Status

Common Tansy

LC — Least Concern

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	Common Tansy	Common Water Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Tansy

Habitat

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

Range

Widely distributed across Asia (China, Japan), Europe (13 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (4 countries).

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Common Tansy

<em>Tanacetum vulgare</em>, common tansy, is a perennial herbaceous plant in the family Asteraceae, native to temperate regions of Asia and Europe and widely naturalized across North America, Australia, and South America. It typically grows in disturbed habitats, roadsides, riverbanks, and waste ground, forming dense colonies through vigorous rhizome spread. The plant bears deeply divided, fernlike leaves and clusters of bright yellow, button-like flower heads in late summer. It is classified as Least Concern on the IUCN Red List given its expansive, growing range. Common tansy contains toxic compounds including thujone and camphor, making it poisonous to livestock and humans in large quantities, though historically it was used as a culinary herb and medicinal plant. Its strong aromatic scent has traditionally been used as an insect repellent. The species is considered invasive in several regions outside its native range. It provides nectar and pollen for various insects. Biological traits such as precise seed output figures, individual lifespan, and biomass data remain poorly documented in standardized assessments.

Common Water Rat

<em>Hydromys chrysogaster</em>, commonly known as the common water rat or rakali, is a semi-aquatic rodent in the family Muridae, native to Australia and New Guinea. It is classified as Least Concern by the IUCN, reflecting its relatively stable population across a broad range of freshwater and estuarine habitats on the Australian continent and associated islands. The species typically inhabits the banks of rivers, lakes, wetlands, and estuaries, where it constructs burrows in streambanks. It is highly adapted for an aquatic lifestyle, with partially webbed hind feet, a flattened head, and a dense waterproof coat. <em>Hydromys chrysogaster</em> is a carnivore, typically feeding on fish, crustaceans, mussels, frogs, and aquatic invertebrates, which it often carries to elevated feeding platforms to consume. The species is nocturnal and crepuscular, most active during early morning and evening hours near the water's edge. Biological traits including average lifespan, body length, and weight remain poorly documented in standardized databases, though adults are generally robust for a rodent, reportedly reaching body lengths of 20–35 cm excluding the tail. Geographic range details for this particular record remain incompletely documented in available data sources. Ecologically, the common water rat is an important apex predator in small-scale freshwater food webs and serves as an indicator species for wetland health in Australian riparian systems.