**Taxonomy of Trillium**
– Established by Carl Linnaeus in 1753
– Initially placed in Liliaceae, later in Trilliaceae
– Assigned to Melanthiaceae by Angiosperm Phylogeny Group in 1998
– Subdivided into subgenus Trillium and subgenus Phyllantherum
– Trillidium Kunth segregated from Trillium in 1850
**Subgenus Classifications**
– Subgenus Trillium (Erectum group)
– 14 species identified in 2022
– Found in North America and Asia
– Includes natural hybrids
– Subgenus Callipetalon
– Includes Trillium grandiflorum and 2 other species
– Flowers have fused stigmas
– Subgenus Delostylis
– Includes Trillium catesbaei and 6 other species
– Limited distribution in southeastern U.S.
– Subgenus Sessilia
– Includes Trillium sessile and 25 other species
– Flowers are sessile with erect petals
**Distribution of Trillium Species**
– Native to North America and Asia
– North America: Over 3 dozen species, most in eastern U.S.
– Asia: Found from the Himalayas to the Kuril Islands, with high diversity in Japan
– Specific species in regions like Sakhalin, Taiwan, and various U.S. states
**Ecology and Conservation**
– Myrmecochorous seeds dispersed by ants
– Susceptible to greening disorder caused by phytoplasmas
– Conservation efforts due to threatened/endangered status and habitat loss
**Medicinal and Cultural Significance**
– Contains sapogenins used in traditional medicine
– Official flower of Ontario and emblem of the province
– Trillium Cup competition, cultural symbolism, and medicinal uses