Trillium undulatum
Painted trillium
Image of Trillium undulatum

Photo by Diane Peirce 

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Key Characteristics

Medium-sized forb (40 cm) of moist acidic woods; leaves broadly oval (3-6 cm wide) with distinct petioles; flowers stalked, white with pink V-shaped marks on each petal.

Status and Rank

  • State Status: E
  • State Rank: S1S2
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
St. Clair82011
Distribution map for Trillium undulatum

Updated 5/15/2018. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


Painted trillium is found in strongly acidic, humus rich soils in low moist hardwoods and mixed hardwoods with hemlock.

Natural Community Types


For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Associated Plants

Red maple, sugar maple, paper birch, yellow birch, eastern hemlock, ash, black oak, swamp oak, wintergreen, royal fern, pipsissewa, pink lady's slipper, cinnamon fern, partridge berry, Canada mayflower, and blueberry.


Maintenance of hydrological regime is important for this species, which requires cool, acid, humus-rich soils, and thus is likely susceptible to excessive logging and other artificial disturbances that impede these natural processes.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.

Survey Methods

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at [Accessed Sep 22, 2018]

More Information

See MNFI Species Abstract


Survey References

Technical References

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