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Trillium discolor Wray ex Hook.
Pale Yellow Trillium
Federal Protection: No US federal protection
State Protection: No Georgia state protection
Global Rank: G3
State Rank: S1S2
Element Locations Tracked in Biotics: Yes
SWAP 2015 Species of Greatest Conservation Need (SGCN): No
SWAP 2025 Species of Greatest Conservation Need (SGCN): Yes
2025 SGCN Priority Tier: High Conservation Concern
Element Occurrences (EOs) in Georgia: 11
Habitat Summary for element in Georgia: Mesic hardwood forests only in Savannah River watershed
Perennial herb with hairless, erect stems 4 - 9 inches (10 - 22 cm) tall. Leaves are 3 in number, held in a whorl at the top of the stem, and are 2.4 - 5 inches long and 1.6 - 2.8 inches wide (6 - 13 cm long and 4 - 7 cm wide), oval to nearly circular, pale green with scattered dark mottles, fading to an unmottled, dull green color with age. A single, erect, stalkless flower is held at the center of the whorl of leaves; it reportedly has a faint sweet or clove smell. Sepals are 3 in number, green, spreading, shorter than petals. Petals are 3 in number, 0.9 - 2 inches long and 0.4 - 0.6 inch wide (2.2 - 5 cm long and 0.9 - 1.5 cm wide), pale yellow or cream-colored, sometimes maroon or green at the base, erect and overlapping or spreading, widest above the middle and abruptly narrowed (“clawed”) near the base; the claw may be green or maroon; one petal has a distinctly pointed tip. The ovary is greenish-white, with 6 slightly winged angles. Stamens are 6 in number, maroon, with vertical pollen sacs (anthers) opening along both sides to release pollen.
Yellow Trillium (Trillium luteum) petals are rich yellow in color, elliptic or lance-shaped, and not abruptly narrowed at the base; its flowers smell strongly of lemon, and the stems may be up to 15 inches (38 cm) tall; it occurs in the Southern Appalachian mountains.
Sweet Betsy or Purple Toadshade (Trillium cuneatum) petals may be bronze or greenish-yellow but never pale yellow; they are lance-shaped and not abruptly narrowed at the base; its leaves are heavily mottled with 2 or 3 shades of pale to dark green; it occurs throughout Georgia.
There are at least 22 named species of Trillium in Georgia, 12 of which are rare:
Trillium decipiens (Mimic Trillium) occurs in moist hardwood forests and limesink forests in southwest Georgia. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=20231
Trillium delicatum (Ocmulgee Trillium) occurs in central Georgia in moist to wet floodplain forests with high pH soils. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=34971
Trillium discolor (Pale Yellow Trillium) occurs in moist hardwood forests only in the Savannah River watershed. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=18320
Trillium flexipes (Bent Trillium) occurs in moist hardwood forests over limestone in northwest Georgia. For more information, see: http://beta.floranorthamerica.org/Trillium_flexipes
Trillium lancifolium (Lanceleaf Trillium) occurs in floodplain forests and lower slopes over basic soils in widely scattered locations in Georgia. For more information, see: http://beta.floranorthamerica.org/Trillium_lancifolium
Trillium persistens (Persistent Trillium) occurs in pine-hemlock-mixed hardwood forests in ravines or along streams in northeast Georgia, often with rhododendrons or in lowbush blueberry thickets. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=19927
Trillium pusillum (Dwarf Trillium) occurs in seasonally wet, red maple-blackgum-oak woods in calcium-rich, clay soils in northwest Georgia. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=18756
Trillium reliquum (Relict Trillium) occurs in mature hardwood forests in rich ravines and on stream terraces, over calcium-rich bedrock such as amphibolite or limestone. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=17442
Trillium simile (Sweet White Trillium) occurs in Georgia's Blue Ridge mountains in rich coves or slopes over mafic rocks, often in or near seepage. For more information, see: http://beta.floranorthamerica.org/Trillium_simile
Trillium sp. [newly recognized, unnamed species] (Lookout Mountain Toadshade) occurs in rich forests in northwest Georgia, southeast Tennessee, and northeast Alabama; it resembles Trillium ludovicianum.
Trillium sp. [newly recognized, unnamed species] (Amicalola Trillium) occurs in Blue Ridge cove forests in Georgia and South Carolina; it resembles Trillium simile.
Trillium sulcatum (Barksdale Trillium) occurs in rich, moist hardwood forests in northwest Georgia. For more information, see: http://beta.floranorthamerica.org/Trillium_sulcatum
Rich cove hardwood forests and bluff forests in the Savannah River drainage.
Trilliums are perennial herbs that send up stems, leaves, and flowers in early spring, after temperatures have risen but before the forest canopy has leafed out. Pale yellow trillium flowers have a spicy or sweet, clove-like smell, suggesting that they are pollinated by insects that are attracted to sweet fragrances (bees) and spicy smells (beetles). After flowering and fruiting, the aboveground plant disappears, persisting through the late summer, fall, and winter as an underground rhizome. Seeds shed in the summer germinate the following spring and, within a year or two, send up a single, spatula-shaped seed leaf (cotyledon) for one year’s growing season. The next year, a true leaf is produced and, in subsequent years, three-leaved plants appear. After 5 - 7 years (possibly fewer in the Coastal Plain), the plant produces a flowering stalk. Trillium seeds have small, fat-rich appendages called elaiosomes that are appealing to ants, yellow jackets, and other wasps, which carry the seed back to their nests, inadvertently dispersing the trillium seeds. Seeds are dispersed longer distances when the fruits are eaten by other animals such as deer and woodchucks. Some seeds are left where they fall if the elaiosomes are eaten off by beetles, resulting in clusters of seedlings near the parent plant. Some trilliums produce clonal rhizome offshoots that develop into immature plants that are eventually separated from the parent plant as the rhizomes decay. Mature trillium plants are very long-lived, perhaps living more than 100 years, but since the rhizome continues to lengthen and produce shoots on one end while the other end decays, it is impossible to determine age from rhizome growth scars.
Surveys are best conducted during flowering (late March–early May).
Georgia, South Carolina, and North Carolina, only in the Savannah River basin.
Logging and clearing of hardwood slopes, damming streams and flooding ravines, overbrowsing by deer, and invasion by exotic pest plants, especially Japanese Honeysuckle and Kudzu.
| Threat 1 | Threat 2 | Threat 3 | |
|---|---|---|---|
| General Threat | Pollution | Climate change & severe weather | None |
| Specific Threat | None | None | None |
Trillium discolor is ranked S1S2 by the Georgia Department of Natural Resources, indicating that the species is imperiled in Georgia. About 10 populations have been documented in Georgia, most on the Chattahoochee National Forest and U.S. Army Corps of Engineers land.
Protect hardwood slope forests from logging and from conversion to pine plantations. Eradicate exotic pest plants, especially Japanese Honeysuckle and Kudzu. Reduce the size of Georgia’s deer herd. Avoid damming streams and flooding of ravines.
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Broyles, B.B., S.M. Smith, T.R. Smith, and J.R. Kindt. 2013. A reevaluation of the use of rhizome scars to age plants of Trillium erectum (Melanthiaceae). American Journal of Botany 100(6): 1155-1161.
Case, F.W., Jr. 2003. Trillium discolor species account Flora of North America, Vol. 26, Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford University Press, New York. http://beta.floranorthamerica.org/Trillium_discolor
Farmer, S.B. 2006. Trillium and the Trillium family (Trilliaceae). http://www.goldsword.com/sfarmer/Trillium
Farmer, S.B. and E.E. Schilling. 2002. Phylogenetic analyses of Trilliaceae based on morphological and molecular data. Systematic Botany 27: 674-692. https://bioone.org/journals/Systematic-Botany/volume-27/issue-4/0363-6445-27.4.674/Phylogenetic-Analyses-of-Trilliaceae-based-on-Morphological-and-Molecular-Data/10.1043/0363-6445-27.4.674.full
Freeman, John D. 1975. Revision of Trillium subgenus Phyllantherum (Liliaceae). Brittonia 27:1-26. https://www.jstor.org/stable/2805646?seq=1#metadata_info_tab_contents
GADNR. 2020. Element occurrence records for Trillium discolor. Georgia Department of Natural Resources, Wildlife Resources Division, Social Circle, Georgia.
Leege, L. M., J. S. Thompson, and D.J. Parris. 2010. The responses of rare and common Trilliums (Trillium reliquum, T. cuneatum, and T. maculatum) to deer herbivory and invasive honeysuckle removal. Castanea 75(4): 433-443.
Marinelli, J. 2005. Perfume for pollinators. Brooklyn Botanic Garden Plants & Gardens News 20(2). http://www.bbg.org/gar2/topics/wildlife/2005su\_makingstink.html
NatureServe. 2020. Trillium discolor species account. NatureServe Explorer. NatureServe, Arlington, Virginia. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.131323/Trillium_discolor
Ohara, M. 1989. Life history evolution in the genus Trillium. Plant Species Biology 4:1-28. https://esj-journals.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1442-1984.1989.tb00044.x
Patrick, T.S. 2007. Trilliums of Georgia. Tipularia, Journal of the Georgia Botanical Society 22: 3 - 22.
Vellend, M., J. Myers, S. Gardescu, and P. Marks. 2003. Dispersal of Trillium seeds by deer: implications for long-distance migration of forest herbs. Ecology 84(4):1067-1072. https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/0012-9658%282003%29084%5B1067%3ADOTSBD%5D2.0.CO%3B2
Weakley, A.S. 2015. Flora of the southern and mid-Atlantic States. University of North Carolina Herbarium, University of North Carolina, Chapel Hill. http://www.herbarium.unc.edu/flora.htm
Zettler, J. A., T. P. Spira, and A. A. Craig. 2001. Yellow Jackets (Vespula spp.) disperse Trillium spp. seeds in Eastern North America. American Midland Naturalist 146(2): 444-446. https://bioone.org/journals/The-American-Midland-Naturalist/volume-146/issue-2/0003-0031(2001)146[0444:YJVSDT]2.0.CO;2/Yellow-Jackets-Vespula-spp-Disperse-Trillium-spp-Seeds-in-Eastern/10.1674/0003-0031(2001)146[0444:YJVSDT]2.0.CO;2.full
Linda G. Chafin
L. Chafin, Dec. 2007: original account.
K. Owers, Feb. 2010: added pictures.
L. Chafin, June 2020: updated original account.
