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U.S. Forest Service

Plant of the Week

USDA Plants distribution map for the species. Trillium sulcatum range map. USDA PLANTS Database.

Trillium pusillum var. pusillum. In this red flowered Trillium sulcatum the species epithet is derived from the sulcate (with longitudinal grooves or furrows) tip of the flower’s stamens. As a result, some people call this the “furrowed trillium.” Image with permission by Hugh & Carol Nourse.

Trillium pusillum var. pusillum. Rainbow Wakerobin (Trillium sulcatum). Photo by T.G. Barnes.

Trillium pusillum var. pusillum. Like many other Trillium species, Trillium sulcatum has white flowered individuals. Image with permission by Thomas Barnes.

Trillium pusillum var. pusillum. Trillium sulcatum’s common rainbow wakerobin is derived from the many different colors the flower can appear as in this yellow flowered individual. Image with permission by Thomas Barnes.

Rainbow Wakerobin (Trillium sulcatum)

By Larry Stritch

Rainbow wakerobin is an herbaceous, long-lived, woodland, perennial wildflower with a narrow distribution primarily west of the Appalachian Mountains; from West Virginia and Virginia; through Kentucky, Tennessee, and North Carolina; into northeast Alabama and northwest Georgia. It is most common on the Cumberland Plateau.

Trillium” is from the Latin “tri” referring to the flower parts occurring in threes, and “llium” from the Latin liliaceous referring to the funnel-shaped flower; and, “flexipes” is from the Latin “sulcus” meaning furrow or grove, refers to the grooved or furrowed (sulcate) tips of the flower’s sepals.

Trillium sulcatum 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 to30 to 70 centimeters tall with a single, terminal flower; leaves (actually bracts) three, green, sub-sessile, obovate, acuminate, 12 to 20 cm long and 7.5 to 22 centimeters wide; flower pedicellate, pedicel erect to sometimes horizontal, flower always above the leaves; petals three, very dark maroon, red, pink, or creamy yellow; spreading and strongly recurved at the tips, ovate, 2 to 5 centimeters long; sepals three, green or green streaked with maroon, the tips sulcate, spreading, 1.5 to 4 centimeters long; fruit red, globose berry.

Trillium sulcatum flowers from early to mid-spring, dependent on elevation. The species occurs in mesic, rich, deciduous forests, sometimes mixed with hemlock, on moist, neutral, soils along stream banks, and north and east facing slopes.

For More Information

  • PLANTS Profile - Trillium sulcatum, Rainbow Wakerobin
  • Flora of North America: Trillium sulcatum
  • Case, F.W., R.B. Case. 1997. Trilliums. Timber Press, Portland, OR.
  • Frett, J. 2007. Trilliums at Mt. Cuba Center: A Visitor’s Guide. 75 pp. Mt. Cuba Center, Inc. Greenville, Delaware.
  • 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.

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