Coast Trillium vs Coastal Flat-body

Trillium ovatum compared with Agonopterix yeatiana

Key Differences

• Coast Trillium is Least Concern while Coastal Flat-body is Near Threatened.

Taxonomic Classification

Rank	Coast Trillium	Coastal Flat-body
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Arthropoda (Arthropods)
Class	Liliopsida (Monocots)	Insecta (Insects)
Order	Liliales (Liliales)	Lepidoptera (Butterflies & Moths)
Family	Melanthiaceae	Depressariidae
Genus	Trillium	Agonopterix
Species	Trillium ovatum	Agonopterix yeatiana

Conservation Status

Coast Trillium

LC — Least Concern

Coastal Flat-body

NT — Near Threatened

Physical Characteristics

Attribute	Coast Trillium	Coastal Flat-body
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coast Trillium

Habitat

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

Range

Found in United States.

Coastal Flat-body

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, and Sweden. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Coast Trillium

Coast trillium (Trillium ovatum) is a spring-flowering perennial herb in the family Melanthiaceae, native to moist, shaded forests of western North America from British Columbia and Alberta south through the Pacific states to central California and east to Montana and Idaho. It grows in mixed conifer and deciduous forest understories, redwood forest, riparian woodland, and coastal range foothills, typically in deep, humus-rich, well-drained soils. Like all trilliums, it produces a whorl of three broad leaves, a single three-petalled flower that opens white and turns pink to deep rose with age, and takes many years to reach flowering maturity from seed. Seeds are dispersed by ants (myrmecochory) attracted to the oil-rich elaiosome attached to each seed. Coast trillium is assessed as Least Concern by the IUCN, though it is a legally protected plant in some US states due to its slow reproductive rate making populations sensitive to disturbance. Illegal collection from the wild for horticulture remains a concern. It is one of the most beloved wildflowers of the Pacific Northwest and is widely cultivated in woodland gardens.

Coastal Flat-body

Agonopterix yeatiana, the coastal flat-body, is a small moth in the family Depressariidae native to coastal and calcareous grassland habitats across western and northern Europe, with records from Belgium, Denmark, and Sweden. Moths in the family Depressariidae, commonly called flat-body moths due to the depressed posture they adopt when resting with wings held flat against the surface, are associated predominantly with umbellifer plants of the family Apiaceae as larval hosts. Agonopterix yeatiana larvae feed on wild carrot (Daucus carota), wild parsnip (Pastinaca sativa), and related coastal and grassland Apiaceae species, inhabiting the open, often calcareous or sandy habitats where these plants grow. Adult moths have greyish-brown forewing with a distinctive pattern of spots and dashes and reach approximately 8–12 millimeters in wingspan. The species is classified as Near Threatened by the IUCN, reflecting declines associated with the loss of traditional hay meadow management, coastal grassland degradation, and scrub encroachment that eliminates the open, flower-rich grassland habitats supporting its host plants. Agricultural intensification has reduced wild umbellifer populations significantly across lowland Europe, reducing food resources for larvae of specialist moths like A. yeatiana.