Plant of the Week

Map of the United States showing states. States are colored green where the species may be found.
Range map of Trillium cernuum. States are colored green where the species may be found.

Northern Nodding Trillium (Penstemon leonardii var. leonardii).
Northern nodding trillium is the most northerly occurring trillium in North America, occurring as far north as Hudson Bay, Ontario, Canada. Image with permission by Diane Peirce.

Northern Nodding Trillium (Penstemon leonardii var. leonardii).
Note the strongly recurved petals, with each petal recurved beyond the spreading, lanceolate sepals. Image with permission by Charles Peirce.

Northern Nodding Trillium (Penstemon leonardii var. leonardii).
In this image from northern Michigan of Trillium cernuum one can see that it is occurring in a northern hardwoods forest. Image with permission by Charles Peirce.

Northern Nodding Trillium (Penstemon leonardii var. leonardii).
Notice the juvenile northern nodding trilliums below the flowering adults. Image with permission by Charles Peirce.

Northern Nodding Trillium (Trillium cernuum)

By Larry Stritch

Northern nodding trillium is an herbaceous, long-lived, woodland, perennial wildflower. Trillium cernuum is the most northerly occurring species of Trillium in North America. In Canada, Trillium cernuum ranges from southeast Saskatchewan and Manitoba in the west, east through Ontario and Quebec, and into the Maritime Provinces all the way east to the island of Newfoundland. In the United States, Trillium cernuum is distributed from eastern North and South Dakota and northeast Iowa, eastward through the Great Lakes states into New England, and southerly into the Mid-Atlantic States to the West Virginia and Virginia border. Reported occurrences south of west-central Virginia are considered misidentifications and are more than likely Trillium flexipes, T. rugelii, or T. catesbaei. (Case & Case, 1997)

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 cernuum from the Latin nodding refers to the flower subtending the leaves. Of special note, Trillium cernuum is the species upon which Linnaeus based the genus Trillium.

Trillium cernuum 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, (commonly 2-3 scapes from a single rhizome). It is 15 to 60 centimeters tall with a single, terminal flower. Leaves (actually bracts) are three, green, sessile to sub-sessile, wider than long, ovate-rhombic, acuminate, 4 to 15 centimeters long and wide. The flower is pedicellate, pedicel strongly recurved or declinate, beneath the leaves. Petals are three, white to creamy white, recurving tips, oblanceolate, 1.5 to 2.5 centimeters long. Sepals are three, green, spreading, lanceolate, 1.5 to 2.5 centimeters long. The fruit is a dark-red, six-sided berry.

Trillium cernuum flowers from early to late spring (dependant on latitude and/or elevation) and into July in northern Canada (Hudson Bay area) and Newfoundland. The species occurs in wet, swampy woodlands, alder thickets in riparian habitats in deciduous woodlands in the southern part of its range and in upland, mixed conifer-deciduous woodlands.

For More Information:

  • PLANTS Profile - Trillium cernuum, northern nodding 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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