Trillium luteum

Trillium luteum
Conservation status
Apparently Secure  (NatureServe)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Liliales
Family:	Melanthiaceae
Genus:	Trillium
Species:	T. luteum
Binomial name
Trillium luteum (Muhl.) Harb.[2]
Synonyms[3]
Trillium luteum Trillium sessile var. luteum Muhl. Trillium sessile f. luteum (Muhl.) Peattie Trillium underwoodii var. luteum (Muhl.) J.F.Macbr. Trillium viride var. luteum (Muhl.) Gleason

Trillium luteum, the yellow trillium^[4][5] or yellow wakerobin,^[6] is a species of flowering plant in the bunchflower family Melanthiaceae. It is a member of the Trillium cuneatum complex, a closely related group of sessile-flowered trilliums. The species is endemic to the southeastern United States, especially in and around the Great Smoky Mountains of eastern Tennessee and western North Carolina.

Description

Trillium luteum is a perennial, herbaceous, flowering plant that persists by means of an underground rhizome. Like all trilliums, it has a whorl of three bracts (leaves) and a single trimerous flower with three sepals, three petals, two whorls of three stamens each, and three carpels (fused into a single ovary with three stigmas).^[7] It has a sessile flower (no flower stalk), erect petals, and mottled leaves.^[8] It grows to 40 cm (16 in) tall by 30 cm (12 in) wide, with lemon yellow scented blooms. The large stalkless triple leaves often have grey-green marbling on the surface. It flowers in April-May beneath the bare branches of deciduous trees.^[9] After flowering and setting seed it goes dormant in summer, before appearing again in late winter.

Taxonomy

In 1813, Gotthilf Heinrich Ernst Muhlenberg described the yellow-petaled variety Trillium sessile var. luteum,^[10] but the taxon was given specific rank (Trillium luteum) by Thomas Grant Harbison in 1901.^[2] The latter is distinguished from T. sessile by its larger size, the mottling of its leaves, shorter filaments, the color of its petals, and the character of its stigmas.^[11] The specific epithet luteum, which means "yellow",^[12] refers to the color of its petals.^[13]

Trillium luteum is a member of the Trillium cuneatum complex, a group of eight taxa including Trillium maculatum and Trillium cuneatum (in the strict sense).^[14] All members of the complex are sessile-flowered trilliums (Trillium subgen. Sessilia).

Distribution and habitat

Trillium luteum is endemic to the southeastern United States, ranging from southeastern Kentucky to northwestern Georgia, with significant populations in and around the Great Smoky Mountains of eastern Tennessee and western North Carolina.^[4][15] It is especially abundant around Gatlinburg, Tennessee.^[13] T. luteum has been widely introduced elsewhere, with known populations in Maryland, Michigan, Ontario, Pennsylvania, South Carolina, and Virginia.^[16] There are hundreds of citizen science observations of T. luteum outside of its natural range, especially in Pennsylvania, Maryland, New York, and Virginia.^[17] A few disjunct populations of yellow sessile-flowered trilliums in central Alabama have been identified as T. luteum but botanists disagree on this point.^[18]

The ranges of T. luteum and T. cuneatum generally do not overlap except in Casey County in southern Kentucky, in southeastern Tennessee, and along the Little Tennessee River on the border between Tennessee and North Carolina. Hybrids will be found along these points of contact, which makes identification difficult.^[19][20]

Cultivation

Though hardy down to −15 °C (5 °F), this plant requires a sheltered position with rich, moist leafmould in a shaded, deciduous woodland setting which mimics its native habitat in North American broadleaf forests. It must be left undisturbed to grow into a large colony. It requires some experience to grow successfully, but nevertheless has gained the Royal Horticultural Society's Award of Garden Merit.^[21][22]

References

1. "Trillium luteum". NatureServe Explorer. NatureServe. Retrieved 5 February 2022.
2. "Trillium luteum (Muhl.) Harb.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens. Retrieved 31 March 2023.
3. "Trillium luteum L.". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 5 February 2022.
4. Case Jr., Frederick W. (2002). "Trillium luteum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
5. Pistrang, Mark. "Yellow Trillium (Trillium luteum)". United States Forest Service. Retrieved 31 March 2023.
6. USDA, NRCS (n.d.). "Trillium luteum". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 31 March 2023.
7. Case Jr., Frederick W. (2002). "Trillium". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford: Oxford University Press. Retrieved 29 March 2023 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
8. Case Jr., Frederick W. (2002). "Trillium subg. Phyllantherum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford: Oxford University Press. Retrieved 29 March 2023 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
9. RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 978-1405332965.
10. "Trillium sessile var. luteum Muhl.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens. Retrieved 31 March 2023.
11. Harbison, T. G. (1901). "New or little known species of Trillium". Biltmore Botanical Studies. 1 (1): 21–22. Retrieved 5 February 2022.
12. Gledhill, David (2008). The Names of Plants (4th ed.). Cambridge University Press. p. 244. ISBN 978-0-521-86645-3.
13. Case & Case (1997), p. 204.
14. Lampley (2021), Ch. 2.
15. Freeman (1975), p. 39.
16. "Trillium luteum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 3 February 2022.
17. "Observations of Trillium luteum". iNaturalist. Retrieved 5 February 2022.
18. Lampley (2021), p. 61.
19. Case & Case (1997), p. 207–208.
20. Freeman (1975), p. 37.
21. "RHS Plant Selector - Trillium luteum". RHS. Retrieved 5 March 2021.
22. "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. November 2018. Retrieved 17 August 2019.

Bibliography

• Case, Frederick W.; Case, Roberta B. (1997). Trilliums. Portland, Oregon: Timber Press. pp. 204–208. 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 31 March 2023.

External links

• Citizen science observations for Trillium luteum at iNaturalist
• Biodiversity Information Serving Our Nation (BISON) occurrence data and maps for Trillium luteum
• Adams, Alan B. (1975). A Study of Trillium cuneatum and T. luteum (MS). University of Tennessee. Retrieved 23 February 2022.