Common Tansy vs Compact Thread-leaf Century Plant

Tanacetum vulgare compared with Agave microceps

Taxonomic Classification

Rank	Common Tansy	Compact Thread-leaf Century Plant
Kingdom same	Plantae (Plants)	Plantae (Plants)
Phylum same	Magnoliophyta (Flowering Plants)	Magnoliophyta (Flowering Plants)
Class	Magnoliopsida (Dicots)	Liliopsida (Monocots)
Order	Asterales (Daisies & Sunflowers)	Asparagales (Asparagales)
Family	Asteraceae (Daisy Family)	Asparagaceae
Genus	Tanacetum	Agave
Species	Tanacetum vulgare	Agave microceps

Evolutionary Relationship

Common Tansy and Compact Thread-leaf Century Plant share a common ancestor at the Phylum level: Magnoliophyta. (Flowering Plants)

Conservation Status

Common Tansy

LC — Least Concern

Compact Thread-leaf Century Plant

LC — Least Concern

Physical Characteristics

Attribute	Common Tansy	Compact Thread-leaf Century Plant
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).

Compact Thread-leaf Century Plant

Habitat

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

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.

Compact Thread-leaf Century Plant

<em>Agave microceps</em>, the compact thread-leaf century plant, is a perennial succulent in the family Asparagaceae native to Mexico, representing one of the smaller members of the ecologically and culturally significant agave genus. Agaves are iconic succulents of arid and semi-arid regions characterised by a rosette of thick, fibrous leaves typically edged with teeth and terminating in a sharp spine. <em>Agave microceps</em> typically forms compact, densely-leaved rosettes with notably narrow, thread-margined leaves, distinguishing it from larger agave species. It inhabits rocky slopes, dry grasslands, and scrublands in its native Mexican range, adapted to well-drained soils and periods of seasonal drought. Like all agaves, it is monocarpic, flowering once after many years of vegetative growth before dying, producing a tall flower spike that provides food resources for bats, hummingbirds, and insects. The species is classified as Least Concern by the IUCN, indicating a stable population without critical current threats, though many agave species face pressure from illegal collection for the horticultural trade and habitat conversion. Agaves play important roles in native ecosystems as food sources for specialist pollinators and as habitat elements on rocky hillsides. Biological traits including average lifespan in the wild, precise rosette dimensions, and population data remain poorly documented for this species compared to more commercially important agaves.