Trillium cuneatum

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Trillium cuneatum, the little sweet betsy,[3] also known as whip-poor-will flower, large toadshade, purple toadshade, and bloody butcher,[4] is a species of flowering plant in the family Melanthiaceae. It is native to the southeastern United States but is especially common in a region that extends from southern Kentucky through central Tennessee to northern Alabama.[5] In its native habitat, this perennial plant flowers from early March to late April (depending on latitude). It is the largest of the eastern sessile-flowered trilliums.[6]

Trillium cuneatum
Trillium Nashville.jpg
Cheekwood Botanical Garden
Nashville, Tennessee

Apparently Secure (NatureServe)[1]
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Liliales
Family: Melanthiaceae
Genus: Trillium
T. cuneatum
Binomial name
Trillium cuneatum
Trillium cuneatum in the USA.svg
US distribution by state
Trillium cuneatum
    • Trillium cuneatum f. luteum J.D.Freeman
    • Trillium hugeri Small
    • Trillium sessile var. praecox Nutt.


Trillium cuneatum has three broad, mottled leaves surrounding a sessile, banana-scented flower. The petals are erect and either maroon, bronze, green, or yellow in color.[7]


Trillium cuneatum was first described by Rafinesque in 1840.[8] The specific epithet cuneatum, which means "narrow below and wide above, wedge-shaped",[9] refers to the tapered shape of the basal half of its flower petal.[10]

As of February 2022, Kew's Plants of the World Online accepts no infraspecific names for Trillium cuneatum.[2] Some authorities recognize the name Trillium cuneatum f. luteum J.D.Freeman,[11] a form marked by the absence of purple pigments from all floral parts. It occurs in the midst of purple-flowered plants throughout the range of the species. Although both have yellow (or greenish-yellow) petals, Trillium cuneatum f. luteum J.D.Freeman is not regarded as the taxonomic or genetic equivalent of Trillium luteum (Muhl.) Harb.[12]

Trillium cuneatum has long been known for its morphological variability across (and even within) geographically distributed populations.[13] Phylogenetic analysis suggests that T. cuneatum is better understood as a species complex that includes T. cuneatum, T. maculatum, and T. luteum, plus two new species previously thought of as T. cuneatum, now proposed as Trillium freemanii sp. nov. and Trillium radiatum sp. nov.[14]

Distribution and habitatEdit

Trillium cuneatum is endemic to the southeastern United States, ranging from Kentucky southward to southern Mississippi, and to the eastern coast of South Carolina. It is native to Alabama, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee.[2] It has been widely introduced elsewhere, with naturalized populations in Illinois, Maryland, Michigan, and Pennsylvania.[15] There are hundreds of observations of T. cuneatum made by citizen scientists outside of its native range, in more than a dozen states, but especially in Virginia, Pennsylvania, Maryland, and New York.[16]

Trillium cuneatum prefers to grow in rich soils in mostly upland woods, especially limestone soils but also at less calcareous sites. It is found at elevations of 50–400 m (160–1,310 ft).[4]


In the southern part of its range, from Mississippi to Georgia, Trillium cuneatum begins to flower in early March, with peak flowering occurring around mid-March. In its northernmost populations, flowering occurs in April.[17][13] In the vicinity of Nashville, Tennessee, fruits were observed to ripen and drop off between July 1 and July 10.[18]

In general, Trillium species are myrmecochorous, that is, ants facilitate seed dispersal in most (if not all) species.[1] Since each seed of T. cuneatum has an attached elaiosome,[18] presumably its seeds are dispersed by ants as well.


  • Case, Frederick W.; Case, Roberta B. (1997). Trilliums. Portland, Oregon: Timber Press. pp. 170–176. ISBN 978-0-88192-374-2.
  • Freeman, J. D. (1975). "Revision of Trillium subgenus Phyllantherum (Liliaceae)". Brittonia. 27 (1): 1–62. doi:10.2307/2805646. JSTOR 2805646. S2CID 20824379.
  • Lampley, Jayne A. (2021). A systematic and biogeographic study of Trillium (Melanthiaceae) (PhD). University of Tennessee. Retrieved 10 February 2022.
  • Shaver, Jesse M. (April 1960). "Trillium cuneatum Raf. in Tennessee" (PDF). J. Of Tenn. Academy of Science. 35 (2): 81–91. Retrieved 1 February 2022.


  1. ^ a b "Trillium cuneatum". NatureServe Explorer. NatureServe. Retrieved 4 February 2022.
  2. ^ a b c "Trillium cuneatum Raf.". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 3 February 2022.
  3. ^ USDA, NRCS (n.d.). "Trillium cuneatum". The PLANTS Database ( Greensboro, North Carolina: National Plant Data Team. Retrieved 15 December 2015.
  4. ^ a b Case Jr., Frederick W. (2002). "Trillium cuneatum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford – via, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  5. ^ Freeman (1975), p. 29.
  6. ^ Pistrang, Mark. "Little Sweet Betsy (Trillium cuneatum)". United States Forest Service. Retrieved 3 February 2022.
  7. ^ Carman, Jack B. (2001). Wildflowers of Tennessee. Highland Rim Press. p. 372.
  8. ^ "Trillium cuneatum Raf.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens. Retrieved 4 February 2022.
  9. ^ Gledhill, David (2008). The Names of Plants (4th ed.). Cambridge University Press. p. 128. ISBN 978-0-521-86645-3.
  10. ^ Case & Case (1997), p. 172.
  11. ^ "Trillium cuneatum f. luteum J.D.Freeman". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens. Retrieved 4 February 2022.
  12. ^ Freeman (1975), pp. 36–37.
  13. ^ a b Freeman (1975), p. 36.
  14. ^ Lampley (2021), Ch. 2.
  15. ^ "Trillium cuneatum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 3 February 2022.
  16. ^ "Observations of Trillium cuneatum outside its native range". iNaturalist. Retrieved 4 February 2022.
  17. ^ Case & Case (1997), p. 173.
  18. ^ a b Shaver (1960), p. 90.

External linksEdit