Plant of the Week
Southern Nodding Trillium (Trillium rugelii)
By Larry Stritch
Southern nodding trillium is an herbaceous, long-lived, woodland, perennial wildflower with a restricted distribution across the southeastern states; from Tennessee and North Carolina south into South Carolina, Georgia, and Alabama. Historically, some botanists attributed this species to Trillium cernuum. This error led to some distribution maps showing a more southerly distribution for T. cernuum. The flowers of T. rugelii are larger and more robust than T. cernuum.
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. Rugelii is named for Ferdinand Rugel an 1800s professional field botanist, who immigrated to the United States in 1840. He collected throughout the southeastern United States; sometimes into Cuba.
Trillium rugelii 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 to15 to 50 centimeters tall with a single, terminal flower. Leaves (actually bracts) are three, green, petiolate, rhombic, broader than long, 5 to 15 centimers long and 6 to 16 centimeters wide. Flowers are pedicellate, strongly recurved below the leaves; sepals three, green, spreading, 1.5 to 4 centimeters long, 0.7 to 1.7 centimeters wide. Petals are three, white or maroon (Case 1997 reports many intermediate color forms when found in mixed colonies with Trillium vaseyi, apparently representing hybrids) broadly ovate to elliptic, 2.5 to 5 centimeters long, 0.8 to 3.5 centimeters wide. The fruit is a dark, reddish-maroon, six-angled berry, 1.5 to 2 centimeters long.
Trillium rugelii flowers from mid-April to early May. The species occurs in rich, mesic, hardwood forests on steep hillsides and stream sides; in Alabama the strongly reflexed flower form occurs in alluvial soils along wooded streams and rivers.
Conservation Note: Trillium rugelii is state threatened in Tennessee. In North Carolina, Tennessee, South Carolina, and Alabama, T. rugelii is ranked S2, imperiled, by the respective State Natural Heritage programs. In Georgia T. rugelii is ranked S3, vulnerable by the Georgia Natural Heritage program.
For More Information:
- PLANTS Profile - Trillium rugelii, Southern 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.