Trillium – Trillium spp.

Trillium - Trillium erectum below, Trillium grandiflorum, left, photos by Steven Foster

Overall At-Risk Score: 46

Latin Name:

Trillium spp.

There are over 35 species of Trillium in North America that all fall under two distinct subgenuses, Trillium and Phyllantherum.

Under the subgenus Trillium are T. catesbaei, T. cernuum, T. erectum, T. flexipes, T. grandiflorum, T. nivale, T. ovatum, T. persistens, T. pusillum, T. rugelii, T. simile, T. sulcatum, T. undulatum, and T. vaseyi.

Under the subgenus Phyllantherum are T. albidum, T. angustpetalum, T. chloropetalum, T. decipiens, T. decumbens, T. discolor, T. foetidissimum, T. gracile, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. oostingii, T. petiolatum, T. recurvatum, T. reliquum, T. sessile, T. stamineum, T. underwoodii, T. viride, and T. viridescens.

Common Name:

Birthroot, Birthwort, Trillium, Wakerobin


Melanthiaceae (Bunchflower family)


Perennial; can be very long-lived.


Trilliums rely on myrmecochory, meaning that its seed dispersal relies primarily on ants carrying away their seed and eating the large oily elaiosomes, leaving just the seed behind to grow.

Geographic Region:

Trilliums occur in parts of every U.S. state except for Alaska, Arizona, Hawaii, Nevada, New Mexico, and Utah and every Canadian province except for Newfoundland and Labrador. Most of the species occur in the eastern U.S.


Each species of Trillium has its own peculiarities regarding the habitat it needs to survive, but as a general rule, most species in the genus prefer open deciduous woods.

Vulnerability of Habitat/Changes of Habitat Quality and Availability:

Loss of habitat is considered one of the more common causes of Trillium populations being in a decline. Several types of Trillium are already limited in where they can live, and development over their habitats can be a big issue depending on the species.

Ability to Withstand Disturbance and Overharvest:

Trilliums are notoriously fragile plants, and picking any part of the plant can result in death, even if the rhizome remains untouched. Because of this, wild-harvest of any kind is detrimental to the health of the species.

Status of Endangered/Threatened (by state):

Subgenus Trillium:

  • T. cernuum is “Exploitably Vulnerable” in New York, “Endangered” in Illinois and Indiana, and “Presumed Extirpated” in Ohio.
  • T. erectum is “Threatened” in Rhode Island, “Exploitably Vulnerable” in New York, and “Endangered” in Illinois.
  • T. flexipes is “Endangered” in Maryland and New York.
  • T. grandiflorum is “Exploitably Vulnerable” in New York and “Endangered” in Maine.
  • T. nivale is “Threatened” in Michigan and Wisconsin, “Rare” in Pennsylvania, and “Endangered” in Kentucky and Maryland.
  • T. persistens is federally recognized as “Endangered” in the United States.
  • T. pusillum is “Endangered” in North Carolina.
  • T. rugelii is “Endangered” in Tennessee.
  • T. undulatum is “Threatened” in Kentucky, “Exploitably Vulnerable” in New York, and “Endangered” in Michigan and Ohio.

Subgenus Phyllantherum:

  • T. decumbens is “Endangered” in Tennessee.
  • T. discolor is “Threatened” in North Carolina.
  • T. lancifolium is “Endangered” in Florida and Tennessee.
  • T. recurvatum is “Threatened: in Michigan.
  • T. reliquum is federally recognized as “Endangered” in the United States.
  • T. sessile is “Threatened” in Michigan and “Endangered” in New York.
  • T. viride is “Endangered” in Illinois and “Probably Extirpated” in Michigan.

Part of Plant Used/Active Medicinal Compounds:

Historically, Native Americans have used whatever species of Trillium that was available for them. It was commonly used to treat boils and irritated or itchy skin, and several tribes used Trilliums as a treatment for various eye issues. At least four groups, the Ccncow, Skagit, Iroquois, and Pomo, recognized Trilliums as poisonous.

Wild Harvesting Impact On Other Species:

Though T. erectum is the species traditionally used as “Beth Root”, many herbal medicine practitioners harvest whatever Trillium species they have available. This can lead to unnecessary stress and population loss of many of the Endangered and Threatened Trillium species.

Recommendations for Industrial and Home Use:

Because of the fragility of Trillium and how many species are already endangered, we recommend staying away from wild-harvest completely, and try to use cultivated Trillium or other, more common plants in its place.


Herb Stories: How We Protect Trillium


  • eFloras, (n.d.), Trillium in Flora of North America, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA. Retrieved August 6, 2019, from
  • Gunther, Erna, 1973, Ethnobotany of Western Washington, Seattle. University of Washington Press. Revised edition, page 25.
  • Herrick, James William, 1977, Iroquois Medical Botany, State University of New York, Albany, PhD Thesis, page 286.
  • O’Connor, R.P. and M.R. Penskar. 2004. Special plant abstract for Trillium undulatum (painted trillium). Michigan Natural Features Inventory, Lansing, MI. 3 pp.
  • Plants Used by the Indians of Mendocino County, California, Contributions from the U.S. National Herbarium 7:295-408., page 329.
  • Schenck, Sara M. and E. W. Gifford, 1952, Karok Ethnobotany, Anthropological Records 13(6):377-392, page 381.
  • U.S. Forest Service, & USDA. (n.d.). Terrific Trilliums. Retrieved August 7, 2019, from
  • USDA. (n.d.). Plants Profile for Trillium (trillium). Results compiled from multiple publications. Retrieved August 6, 2019, from

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