Trillium kurabayashii

J.D. Freeman

Giant Purple Trillium

G3Vulnerable Found in 6 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
VulnerableIUCN
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.132440
Element CodePMLIL200F0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNVulnerable
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderLiliales
FamilyMelanthiaceae
GenusTrillium
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.
Taxonomic Comments
Trillium kurabayashii was described in 1975 by Freeman and is considered distinct from T. angustipetalum based on flower morphology, namely sessile and acuminate bracts, longer and wider sepals, and much wider petals.Trillium kurabayashii and T. angustipetalum were then synonymized by Ness (1993); however, experts agree that they are distinct species based on morphologic and molecular evidence (pers. comm. A. Floden, Flora of North America).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2020-12-12
Change Date2020-12-12
Edition Date2019-10-22
Edition AuthorsOliver, L. and K. Wayman
Threat ImpactMedium
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Trillium kurabayashii occurs in California and Oregon in two distinct populations: in the Sierra Nevadas and disjunct northwestward in the Klamath Mountains. The calculated Global Rank does not take into account the questionable population in the Sierra Nevadas given that experts have correctly identified some of Freeman's specimens as T. angustipetalum. More study is needed to better understand the Sierra Nevada plants, and specifically the collections from the southern Sierra Nevadas. Given the relatively small populations and number of populations (fewer than 50) this species is also more vulnerable to random catastrophic events. Logging and non-native species are also threats.
Range Extent Comments
This species occurs in two distinct populations: one in California in the Sierra Nevada mountains from Del Norte County to Butte County, and the other in northwestern California in Humboldt County north to Curry County, Oregon. There are some misidentifications in the Sierra Nevada mountains that are likely T. angustipetalum.
Threat Impact Comments
Elk herbivory is a threat, as is competition with non-native blackberry. Logging is also a threat to this species in California (pers.comm., CNPS 2019).
Ecology & Habitat

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). 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).

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 - Hardwood
Other Nations (1)
United StatesN3
ProvinceRankNative
CaliforniaSNRYes
OregonS1Yes
Threat Assessments
ThreatScopeSeverityTiming
5 - Biological resource usePervasive (71-100%)Moderate or 11-30% pop. declineHigh (continuing)
5.3 - Logging & wood harvestingPervasive (71-100%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesPervasive (71-100%)Slight or 1-10% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesPervasive (71-100%)Slight or 1-10% pop. declineHigh (continuing)

Plant Characteristics
DurationPERENNIAL, Long-lived
Economic Value (Genus)Yes
Roadless Areas (6)
California (4)
AreaForestAcres
Orleans Mtn.Klamath National Forest49,090
Orleans Mtn. BSix Rivers National Forest17,183
Orleans Mtn. CSix Rivers National Forest15,589
Siskiyou BSix Rivers National Forest18,871
Oregon (2)
AreaForestAcres
North KalmiopsisSiskiyou National Forests91,560
Shasta CostaSiskiyou National Forests14,420
References (18)
  1. Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, eds. 2012. The Jepson manual: vascular plants of California. 2nd edition. University of California Press, Berkeley, CA. 1568 pp.
  2. 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.
  3. Case, F.W. and R.B. Case. 1997. Trilliums. Timber Press, Portland Oregon.
  4. 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.
  5. 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.
  6. Fernald, M.L., and A.C. Kinsey. 1943. Edible Wild Plants of Eastern North America. Idlewild Press, Cornwall-on-Hudson, NY. xiv+452 pp.
  7. 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.
  8. Freeman, J.D. 1975. Revision of Trillium subgenus Phyllantherum (Liliaceae). Brittonia 27:1-62.
  9. 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.
  10. Klest, S.M. 2002. Propagation Protocol for Western Trilliums. Native Plants Journal 3(1):22-23.
  11. 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.
  12. 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.
  13. Ohara, M. 1989. Life history evolution in the genus Trillium. Plant Species Biology 4:1-28.
  14. 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.
  15. 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.
  16. 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.
  17. 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
  18. 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.