Trillium discolor
Wray ex Hook.
Faded Trillium
G3VulnerableGlobal Rank
Near threatenedIUCN
MediumThreat Impact
TreeFloyd, CC BY-NC 4.0
Becky, CC BY-NC 4.0
Becky, CC BY-NC 4.0
Becky, CC BY-NC 4.0
Sarah Kelsey, CC BY-NC-SA 4.0
Scott Ranger, CC BY-NC 4.0
Brian Finzel, CC BY-SA 4.0
Identity
Unique IDELEMENT_GLOBAL.2.131323
Element CodePMLIL20090
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNNear threatened
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderLiliales
FamilyMelanthiaceae
GenusTrillium
Other Common Names
Mottled Wakerobin (EN) mottled wakerobin (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2019-10-22
Change Date2008-04-30
Edition Date2019-10-22
Edition AuthorsCrowell, Jr., W. L. (1996), rev. D. Gries (1999), rev. L. Oliver (2019)
Threat ImpactMedium
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Trillium discolor is restricted to mountainous areas of the Savannah River drainage of North Carolina, South Carolina, and Georgia. Trillium discolor populations are currently threatened by habitat alteration resulting from commercial and residential development, silvicultural practices, and inundation from dam construction. Trillium discolor sites may be threatened by other land-use changes including roadway construction and by invasive species.
Range Extent Comments
Trillium discolor is restricted to mountainous areas of the Savannah River drainage of North Carolina, South Carolina, and northeastern Georgia.
Occurrences Comments
In South Carolina, Trillium discolor is readily found in coves derived from mafic substrates in the Inner Piedmont of three counties with large publicly or privately owned conservation properties such as Sumter National Forest and Jocasee Gorges. More sites will inevitably be discovered as these areas are better documented (B. Pittman, pers. comm. 2007).
Threat Impact Comments
The greatest threat to this species is damage from invasive hogs and from invasive plants, particularly Ligustrum sinense. Threats from wild hogs have been documented in Oconee County, South Carolina (pers. comm. H. Brown 2019). Threats from other exotic plant species exist, especially from aggressive ground covering species including: Hedera helix, Lonicera japonica, and Peuraria lobata. Manual removal of exotic plants is recommended over herbicide use. There is concern that Viburnum setigerum will spread into the areas where this species occurs. There is also concern that white tailed deer are impacting the species. Deer predation may not have serious impacts on large populations but could severely impact smaller populations.
Trillium discolor populations have been threatened by habitat alteration from commercial and residential development, inundation from dam construction, silvicultural practices, and silvicultural practices. Land-use change to commercial and residential development is present in some potential habitat areas for T. discolor. Although this pressure is presently not a severe threat throughout T. discolor's range, the threat may increase as rural areas continue to become more developed. Trillium discolor sites may be damaged due to inundation from dam construction. The low lying habitat where T. discolor occurs is similar to the habitat of Shortia galacifolia, where inundation from hydroelectric projects along the Savannah River has been documented (Dunn and Jones 1979). Along smaller tributaries, flooding from beaver dams may also threaten some populations.
Silvicultural practices generally create openings in the forest canopy that can dry the substrate and reduce habitat quality. While Trillium discolor may respond favorably to increased sunlight in the short term, the long term decrease of soil moisture will reduce habitat quality over time. If logging cannot be avoided, extreme care should be given to avoiding Trillium discolor plants and controlling sedimentation and erosion control. Clearcutting and power line rights-of-way could have major impacts by eliminating the canopy. The trend of increasing temperatures coupled with decreased moisture in the southeast may exacerbate current disturbances and gradually impact population growth overtime (pers. comm. H. Brown 2019).
Harvesting for commercial trade is not currently a significant threat, although harvesting for personal collections is a high potential threat. Collection for garden exhibits may create or increase a demand for the species that could lead to more wild harvesting. Collections for scientific and educational purposes are sporadic and constitute a low threat. Any collection should be gathered from larger populations and should be monitored.
Trillium discolor populations have been threatened by habitat alteration from commercial and residential development, inundation from dam construction, silvicultural practices, and silvicultural practices. Land-use change to commercial and residential development is present in some potential habitat areas for T. discolor. Although this pressure is presently not a severe threat throughout T. discolor's range, the threat may increase as rural areas continue to become more developed. Trillium discolor sites may be damaged due to inundation from dam construction. The low lying habitat where T. discolor occurs is similar to the habitat of Shortia galacifolia, where inundation from hydroelectric projects along the Savannah River has been documented (Dunn and Jones 1979). Along smaller tributaries, flooding from beaver dams may also threaten some populations.
Silvicultural practices generally create openings in the forest canopy that can dry the substrate and reduce habitat quality. While Trillium discolor may respond favorably to increased sunlight in the short term, the long term decrease of soil moisture will reduce habitat quality over time. If logging cannot be avoided, extreme care should be given to avoiding Trillium discolor plants and controlling sedimentation and erosion control. Clearcutting and power line rights-of-way could have major impacts by eliminating the canopy. The trend of increasing temperatures coupled with decreased moisture in the southeast may exacerbate current disturbances and gradually impact population growth overtime (pers. comm. H. Brown 2019).
Harvesting for commercial trade is not currently a significant threat, although harvesting for personal collections is a high potential threat. Collection for garden exhibits may create or increase a demand for the species that could lead to more wild harvesting. Collections for scientific and educational purposes are sporadic and constitute a low threat. Any collection should be gathered from larger populations and should be monitored.
Ecology & Habitat
Diagnostic Characteristics
Among sessile Trilliums, T. discolor is unique for its petal color and shape. The spatulate, apiculate petals are a pale yellow (almost white) or a pale sulfur yellow. The relatively small ovary is half the length of the stamens. The bud of T. discolor is distinctive, being the only sessile-flowered Trillium in the southeast with apiculate buds. The flower has a spicy clove-like fragrance.
Habitat
Habitats of Trillium discolor include: wooded slopes usually on circumneutral to basic soils (Radford et al. 1968); rich cove forests (Weakley In Progress); rich to rather open oak-pine woods and cane brakes; on rocky bluffs, ravine slopes, or alluvial clay soils (Freeman 1975); mesic lower slopes of drainages over amphibolite (R. Sutter pers. comm.).
Sites may be low to moderate in elevation, mesic, sheltered and may be quite rocky. The dense forest canopy can contain a diverse mixture of mesophytic trees such as Liriodendron tulipifera, Acer saccharum, Betula lenta, Prunus serotina, and Tsuga canadensis. The open understory may contain Cornus florida, Carpinus carolina, Magnolia tripetala, and Ostrya virginiana. Shrub layer is open and sparse and may include Lindera benzoin, Cornus alterniflora, and Hydrangea arborescens. The herb layer is lush and very diverse, with a number of rare species often present. Some species present in the herb layer are Cimicifuga racemosa, Trillium erectum, Impatiens pallida, I. capensis, Arisaema triphyllum, and Viola spp. Some of the rare vascular plants often found in these areas include Isotria medoloides, and Panax quinquefolius (Schafale and Weakley 1990).
Sites may be low to moderate in elevation, mesic, sheltered and may be quite rocky. The dense forest canopy can contain a diverse mixture of mesophytic trees such as Liriodendron tulipifera, Acer saccharum, Betula lenta, Prunus serotina, and Tsuga canadensis. The open understory may contain Cornus florida, Carpinus carolina, Magnolia tripetala, and Ostrya virginiana. Shrub layer is open and sparse and may include Lindera benzoin, Cornus alterniflora, and Hydrangea arborescens. The herb layer is lush and very diverse, with a number of rare species often present. Some species present in the herb layer are Cimicifuga racemosa, Trillium erectum, Impatiens pallida, I. capensis, Arisaema triphyllum, and Viola spp. Some of the rare vascular plants often found in these areas include Isotria medoloides, and Panax quinquefolius (Schafale and Weakley 1990).
Ecology
There is very little information on the reproductive biology of this species of Trillium. Plants flower from late March to early May (Radford et al. 1968, Weakley In Progress). The general life cycle is similar to that of most Trillium species: flowers appear in the early spring, an oval-shaped berry-like capsule fruit matures in the early to mid summer, and the plant then perenates to its rhizome after the fruit matures. Plant dormancy may also play a factor in the life cycle of this species (R. Sutter pers. comm.).
The fruits do not appear adapted for long distance dispersal and most likely fall near the parent plant. Chances for extra-population dispersal are poor. Capsules could be transported by water, animals, or insects. Seed morphology may be conducive to myrmecochory. Seed dispersal by ants, observed with T. petiolatum, may also take place with T. discolor.
Trillium discolor grows from rhizomes that are usually compact with very short internodes, suggesting a very slow growth rate (Freeman 1975).
The fruits do not appear adapted for long distance dispersal and most likely fall near the parent plant. Chances for extra-population dispersal are poor. Capsules could be transported by water, animals, or insects. Seed morphology may be conducive to myrmecochory. Seed dispersal by ants, observed with T. petiolatum, may also take place with T. discolor.
Trillium discolor grows from rhizomes that are usually compact with very short internodes, suggesting a very slow growth rate (Freeman 1975).
Reproduction
Trillium seeds have an elaiosome, an oily, lipid-rich attachment that is highly attractive to ants. The ants carry the seeds to their nest, eat the attachment, and leave the seeds in tunnels in their nests (FNA 2002a, Leege et al. 2010). The seeds later germinate en masse (Case and Case 1997). Miller and Kwit (2018) found that T. discolor had limited seed dispersal effectiveness compared to other more widespread Trillium species.
Yellow jackets (Vespula spp.) and other wasps are similarly attracted to the elaiosome. Yellow jackets are documented seed dispersers for three species (T. catesbaei, T. cuneatum, T. undulatum) (Zettler et al. 2001). Ants carry the seeds an average of about 1m whereas yellow jackets disperse seeds an average of 1.4m (Chafin 2010, Zettler et al. 2001). Long distance dispersers include mammals, such as white-tailed deer (Odocoileus virginianus) and woodchucks (Marmota monax) (Chafin 2010, Vellend et al. 2006). Similarly, it is suspected that elk (Cervus canadensis) and mule deer (Odocoileus hemionus) of the western U.S.A. are capable of dispersing seeds over long distances (Bartuszevige and Endress 2008).
All Trillium have rhizomes but the frequency of asexually reproduction varies (Chauhan et al. 2019, FNA 2002a, Ohara 1989).
Trillium seeds exhibit a somewhat unique kind of dormancy called deep simple double morphophysiological dormancy, meaning they require two winters and one summer to complete dormancy break. After dispersal, roots (radicles) emerge in the first spring and leaves (epicotyls) begin growing in the second spring. The result is that Trillium seeds are generally about 1.5-2 years before they are non-dormant. If root emergence does not occur during the first spring, the next opportunity for root emergence would be the third spring and epicotyl emergence would occur during the fourth spring after dispersal (Walck et al. 2005). Age to maturity, or flowering, is variable and has been recorded from 4 to 20 years depending on growing conditions (Case and Case 1997).
Yellow jackets (Vespula spp.) and other wasps are similarly attracted to the elaiosome. Yellow jackets are documented seed dispersers for three species (T. catesbaei, T. cuneatum, T. undulatum) (Zettler et al. 2001). Ants carry the seeds an average of about 1m whereas yellow jackets disperse seeds an average of 1.4m (Chafin 2010, Zettler et al. 2001). Long distance dispersers include mammals, such as white-tailed deer (Odocoileus virginianus) and woodchucks (Marmota monax) (Chafin 2010, Vellend et al. 2006). Similarly, it is suspected that elk (Cervus canadensis) and mule deer (Odocoileus hemionus) of the western U.S.A. are capable of dispersing seeds over long distances (Bartuszevige and Endress 2008).
All Trillium have rhizomes but the frequency of asexually reproduction varies (Chauhan et al. 2019, FNA 2002a, Ohara 1989).
Trillium seeds exhibit a somewhat unique kind of dormancy called deep simple double morphophysiological dormancy, meaning they require two winters and one summer to complete dormancy break. After dispersal, roots (radicles) emerge in the first spring and leaves (epicotyls) begin growing in the second spring. The result is that Trillium seeds are generally about 1.5-2 years before they are non-dormant. If root emergence does not occur during the first spring, the next opportunity for root emergence would be the third spring and epicotyl emergence would occur during the fourth spring after dispersal (Walck et al. 2005). Age to maturity, or flowering, is variable and has been recorded from 4 to 20 years depending on growing conditions (Case and Case 1997).
Terrestrial Habitats
Forest/WoodlandForest - HardwoodForest - MixedWoodland - MixedCliff
Other Nations (1)
United StatesN3
| Province | Rank | Native |
|---|---|---|
| North Carolina | S1 | Yes |
| Georgia | S1 | Yes |
| South Carolina | S4 | Yes |
Threat Assessments
| Threat | Scope | Severity | Timing |
|---|---|---|---|
| 1 - Residential & commercial development | Restricted (11-30%) | Moderate - slight | High (continuing) |
| 1.1 - Housing & urban areas | Restricted (11-30%) | Moderate - slight | High (continuing) |
| 2 - Agriculture & aquaculture | Unknown | Unknown | High (continuing) |
| 7 - Natural system modifications | Unknown | Neutral or Potential Benefit | Insignificant/negligible or past |
| 7.2 - Dams & water management/use | Unknown | Neutral or Potential Benefit | Insignificant/negligible or past |
| 7.2.10 - Large Dams | Unknown | Neutral or Potential Benefit | Insignificant/negligible or past |
| 8 - Invasive & other problematic species, genes & diseases | Pervasive (71-100%) | Moderate or 11-30% pop. decline | High (continuing) |
| 8.1 - Invasive non-native/alien species/diseases | Pervasive (71-100%) | Moderate or 11-30% pop. decline | High (continuing) |
| 8.2 - Problematic native species/diseases | Pervasive (71-100%) | Serious - moderate | High (continuing) |
| 9 - Pollution | Unknown | Unknown | High (continuing) |
| 9.3 - Agricultural & forestry effluents | Unknown | Unknown | High (continuing) |
| 9.3.2 - Soil erosion, sedimentation | Unknown | Unknown | High (continuing) |
| 11 - Climate change & severe weather | Pervasive (71-100%) | Unknown | High (continuing) |
Plant Characteristics
DurationPERENNIAL, Long-lived
Economic Value (Genus)Yes
Roadless Areas (1)
North Carolina (1)
| Area | Forest | Acres |
|---|---|---|
| Cheoah Bald | Nantahala National Forest | 7,795 |
References (24)
- Bartuszevige, A.M., and B.A. Endress. 2008. Do ungulates facilitate native and exotic plant spread? Seed dispersal by cattle, elk and deer in northeastern Oregon. Journal of Arid Environments 72: 904-913.
- Case, F.W. and R.B. Case. 1997. Trilliums. Timber Press, Portland Oregon.
- Chafin, L. G. 2010d. Species account for <i>Trillium persistens </i>for Georgia Department of Natural Resources. Online. Available: georgiawildlife.com/sites/default/files/uploads/wildlife/nongame/pdf/accounts/plants/trillium_persistens.pdf.
- Chauhan, H., A. Bisht, I. Bhatt, A. Bhatt, and D. Gallacher. 2019. <i>Trillium </i>- toward sustainable utilization of a biologically distinct genus valued for traditional medicine. The Botanical Review 85(3): 252-272.
- Dunn, B.A. and S.M. Jones. 1979. Geographic distribution of Shortia galacifolia in Oconee and Pickins counties, South Carolina. The Journal of the Elisha Mitchell Scientific Society 95(1): 31-41.
- Fernald, M.L., and A.C. Kinsey. 1943. Edible Wild Plants of Eastern North America. Idlewild Press, Cornwall-on-Hudson, NY. xiv+452 pp.
- Flora of North America Editorial Committee (FNA). 2002a. Flora of North America north of Mexico. Vol. 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford Univ. Press, New York. xxvi + 723 pp.
- Freeman, J.D. 1975. Revision of Trillium subgenus Phyllantherum (Liliaceae). Brittonia 27:1-62.
- Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
- Klest, S.M. 2002. Propagation Protocol for Western Trilliums. Native Plants Journal 3(1):22-23.
- Leege, L. M., J. S. Thompson, D.J. Parris. 2010. The Responses of Rare and Common Trilliums (<i>Trillium reliquum</i>, <i>T. cuneatum</i>, and <i>T. maculatum</i>) to Deer Herbivory and Invasive Honeysuckle Removal. Castanea 75(4): 433-443.
- Lewis, Walter H., and Memory P.F. Elvin-Lewis. 1977. Medical Botany: Plants Affecting Man's Health. John Wiley and Sons, New York, New York. 515 p.
- Miller, C. and C. Kwit. 2018. Overall seed dispersal effectiveness is lower in endemic <i>Trillium </i>species than in their widespread congeners. American Journal of Botany 105 (11): 1847-1857.
- Miller, C. N., S. R. Whitehead and C. Kwit. 2020. Effects of seed morphology and elaiosome chemical composition on attractiveness of five <i>Trillium </i>species to seed-dispersing ants. Ecology and Evolution 10: 2860-2873. DOI: 10.1002/ece3.6101
- Ohara, M. 1989. Life history evolution in the genus Trillium. Plant Species Biology 4:1-28.
- Radford, A.E., H.E. Ahles, and C.R. Bell. 1968. Manual of the vascular flora of the Carolinas. Univ. North Carolina Press, Chapel Hill, NC. 1183 pp.
- Rahman, S., M. Ismail, M. Khurram, I. Ullah, F. Rabbi, and M. Iriti. 2017. Bioactive steroids and saponins of the genus <i>Trillium. </i> Molecules 22(12): 2156.
- Rawinski, T. 1987. Isotria medeoloides, Element Stewardship Abstract. The Nature Conservancy.
- Schafale, M. P., and A. S. Weakley. 1990. Classification of the natural communities of North Carolina: Third approximation. North Carolina Natural Heritage Program, Raleigh, North Carolina. 325pp.
- Trillium workshop group. 2019. , L. L. Gaddy, A. Floden, A. Frances, A. Highland, D. Leaman, T. Littlefield, C. Meredith, S. O'Bryan, L. Oliver, E. Schilling, A. Schotz, A. Walker, K. Wayman. Status assessment workshop at Mt. Cuba Center, Oct. 21-23, 2019.
- Vellend, M., J. Myers, S. Gardescu, and P. Marks. 2003. Dispersal of <i>Trillium</i> seeds by deer: Implications for long-distance migration of forest herbs. Ecology 84(4):1067-1072.
- Walck, J.L., J.M. Baskin, C.C. Baskin, and S.N. Hidayati. Defining transient and persistent seed banks in species with pronounced seasonal dormancy and germination patterns. Seed Science Research 15: 189-196. DOI: 10.1079/SSR2005209
- Weakley, A.S. 1996. Flora of the Carolinas and Virginia: working draft of 23 May 1996. The Nature Conservancy, Southeast Regional Office, Southern Conservation Science Dept., Chapel Hill, North Carolina. Unpaginated.
- Zettler, J. A., T. P. Spira, and A. A. Craig. 2001. Yellow Jackets (<i>Vespula</i> spp.) Disperse <i>Trillium</i> (spp.) Seeds in Eastern North America. American Midland Naturalist 146(2):444-446.