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U.S. Forest Service

Plant of the Week

Species range map. Trillium undulatum range map. USDA PLANTS Database.

Trillium undulatum. A very nice grouping of Trillium undulatum. Note the two non-flowering plants just to the right of the flowering plants. Image with permission by Al Menk.

Trillium undulatum. A lone painted trillium in a mixed hemlock / hardwood forest with numerous wild lily of the valley (Maianthemum canadense) on the forest floor. Image with permission by Al Menk.

Trillium undulatum. Observe the wavy-margined petals of this painted trillium flower and note how the reddish purple splotch at the bases of the petals serves as a pollinator guide. Image with permission by Larry Lynch.

Trillium undulatum. Note the coloration of the leaves, a maroon-infused green. Image with permission by Diane Peirce.

Painted Trillium (Trillium undulatum)

By Larry Stritch

Painted trillium is an herbaceous, long-lived, woodland, perennial wildflower with a broad distribution across New England, New York and Pennsylvania thence south in a narrow band in the Appalachian Mountains from West Virginia and Virginia to the high mountains of Georgia; and in Canada from Ontario, Quebec and the maritime provinces to Nova Scotia.

“Trillium”, from the Latin tri, refers to the flower parts occurring in threes; “llium” from the Latin liliaceous, refers to the funnel-shaped flower; and, “flexipes”, from the Latin undulatum (i.e., wavy) refers to the petals’ wavy margins.

Trillium undulatum has a short, thick rhizome from which a sheath (highly modified leaf called a cataphyll) enclosed scape (stalk of the inflorescence) emerges from the ground to 10 to 45 centimeters tall. It has a single, terminal flower. Leaves (actually bracts) are three, dark green infused with maroon, petiolate, lanceolate, acuminate, 5 to 17 centimeters long and 4 to 12 centimeters wide. The flower is pedicellate, with the pedicel ascending to erect. Sepals are three, dark red to dark maroon green, spreading, 1.5 to 4 centimeters long, and 0.5 to 1.0 centimeters wide. Petals are three, wavy-margined, white with a central red to reddish purple splotch at the base, lanceolate to obovate, acuminate, 1.4 to 1.8 centimeters long. Fruit is a scarlet, three-angled berry, 1 to 2 centimeters long.

Trillium undulatum flowers from early to late spring (dependant on latitude and/or elevation). The species occurs in mesic, northern hardwoods, mixed conifer-hardwood forests, to pinewoods and high-elevation red spruce forests in the central Appalachian Mountains in very acidic humus-rich soils.

For More Information

  • PLANTS Profile - Trillium undulatum, painted trillium
  • Case, F. W. and R. B. Case. 1997. Trilliums. 284 pp. Timber Press. Portland, Oregon.
  • Jacobs, D. L. and Jacobs R. L. 1997. Trilliums in Woodland and Garden: American Treasures. 152 pp. Eco-Gardens. Decatur, Georgia.
  • Patrick, T. 2007. Trilliums of Georgia. Tipularia 22: 3-22. Georgia Botanical Society.
  • Frett, J. 2007. Trilliums at Mt. Cuba Center: A Visitor’s Guide. 75 pp. Mt. Cuba Center, Inc. Greenville, Delaware.

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