Family Lilaceae
Genus: Trillium. Genus of three dozen species of woodland perennials from North America (Zone 5). Notable for early and showy spring flower. Many are native to Wisconsin.


Photograph Trillium species 'variety'
Description and comments
Trillium catesbaei
Flowers hang below leaves.
Trillium cernuum
(Nodding Trillium)
White flowers with distinctive purple stamens. Flowers frequently hang below leaves.
Trillium cuneatum
(Purple Toadshade Trillium)
Flower sessile. Erect maroon petals. Maroon veined green sepals, mostly erect. Lightly mottled leaves.
Trillium erectum
(Red Trillium)
Red petals.
Trillium flexipes
White flowers.
Trillium grandiflorum
(Great White Trillium)
White showy flowers. Flowers held upright with wavy petals frequently curled back.
Trillium grandiflorum forma polymerum
Polyploid.
Trillium luteum
(Yellow Trillium)
Yellow petals, sessile flower, and mottled leaves.
Trillium recurvatum
(Prairie Trillium)
Maroon to dark red flowers. Small flower borne above leaves with no stalk.
Trillium stamineum
(Twisted Trillium)
Flower sessile. Anthers extrose (facing away from ovary). Twisted maroon petals. Maroon stamens and maroon to green sepals.
Trillium underwoodii
(Underwood's Trillium)
Maroon flowers. Flowers borne above leaves with no stalk (sessile). Distinctive mottling on leaves.
Trillium vaseyi
(Sweet Trillium)
Maroon petals, pedicel flower that hangs below leaves.
Trillium hybrid
Cross between species.


Trillium Identification Key Common Species

1a. Flowers are held on stems (flower "stems" are technically called a pedicel). Leaves are mottled. Go to step 2.

1b. Stemless flowers are just above leaves (botanically described as sessile). Leaves are uniformly green. Go to step 5.

2a. Petals white, or green-white. Go to step 3.

2b. Petals red or maroon. Go to step 4.

3a. Large white petals, 2-3 inches long. Flower held strongly erect, above leaves. You have Trillium grandiflorum.

Note: Mycoplasma infected flowers of Trillium grandiflorum form showy green-white petals.

3b. Small white petals, less than 1 inch long. Flower nodding beneath leaves. Anther sac about equal to the size of the filament. You have Trillium cernuum.

4a. Flower held erect, above leaves. You have Trillium erectum.

4b. Flower nodding beneath leaves. You have Trillium vaseyi.

5a. Green sepals hang down below leaves. Anthers curve inward. You have Trillium recurvatum.

5b. Green sepals show above leaves. Anthers erect and straight. Go to step 6.

6a. Petals yellow. You have Trillium luteum.

6b. Petals red or maroon. Go to step 7.

7a. Yellow pollen sacs of anthers face center of flower (botanically described as, anther dehiscence introrse to ovary). You have Trillium sessile.

7b. Yellow pollen sacs of anthers do not face center of flower (botanically described as, an anther dehiscence latrorse to ovary). You have Trillium underwoodii.

Click here for additional Trillium information.


    List of Common Trillium Species
  • Trillium catesbaei (Catesby's Trillium, Bashful Wakerobin USDA). Pink to rose petals, pedicel flower that hangs below leaves, and green leaves. Does not form clumps. Easy to grow in cultivation. Native to Alabama through Virginia. L12.
  • Trillium cernuum (Nodding Trillium, Whip-Poor-Will Flower USDA). White petals, pedicel flower that hangs below leaves, and bright green leaves. Native to northern Illinois and northern states.
  • Trillium cuneatum (Purple Toadshade Trillium, Little Sweet Betsy USDA). Flower sessile. Erect maroon petals. Maroon veined green sepals, mostly erect. Lightly mottled leaves. Native to Tennessee, Alabama, and Mississippi. L21.
  • Trillium erectum (Red Trillium USDA). Red to purple petals, pedicel flower held erect, and bright green leaves. Clump forming. Native to Michigan and northeast states. Beige form or interspecific hybrid. L12, L21. Fragrance: Wet dog. Key: T. flexipes ovary white, T. erectum form album (L21, B33) ovary maroon.
  • Trillium flexipes (Bent Trillium, Nodding Wakerobin USDA). White petals (does not turn pink with age), pedicel flower held flexed (bent), and light green leaves. Clump forming. Native to Wisconsin through Tennessee. L12. Key: T. flexipes ovary white, T. erectum form album ovary maroon.
  • Trillium grandiflorum (Great White Trillium WI, White Trillium USDA). Large white petals, pedicel flower, and dark green leaves. Native to Illinois, also most northern and eastern states. Double flower Trillium grandiflorum forma polymerum, horticulturally called "floro plenum". L13.
  • Trillium luteum (Yellow Trillium, Yellow Wakerobin USDA). Yellow petals, sessile flower, and mottled leaves. Native to Tennesse and Kentucky. L21, B31. Fragrance: Sweet lemon.
  • Trillium nivale (Snow Trillium USDA). L12.
  • Trillium recurvatum (Prairie Trillium WI, Bloody Butcher USDA). Maroon to burgundy petals with downwardly curved setals, sessile flower, and mottled petiolate leaves. Native to Missouri, Illinois, Indiana, and Wisconsin. L22, L21.
  • Trillium sessile (Sessile Trillium, Toadshade USDA). Maroon to burgundy petals with sepals flat on leaves, flower sessile, and mottled sessile leaves. Native to Missouri, Illinois, Indiana, and Ohio.
  • Trillium stamineum (Twisted Trillium, Blue Ridge Wakerobin USDA). Twisted maroon petals. Maroon stamens and maroon to green sepals, sessile flower, and lightly mottled sessile leaves. Native to Tennessee and Alabama. Fragrance: strong carrion odor.
  • Trillium underwoodii (Underwood's Trillium, Longbract Wakerobin USDA). Red petals, sessile flower, and distinctively mottled leaves. Native to Alabama.
  • Trillium undulatum (Painted Trillium USDA). Wavy white petals with v-shaped red interior mark, pedicel flower held erect, and dark green leaves. Does not form clumps. Native to Tennessee through Maine, maybe native to Wisconsin. L13. Difficult to cultivate.
  • Trillium vaseyi (Sweet Trillium, Sweet Wakerobin USDA). Maroon petals, pedicel flower that hangs below leaves. Native to Tennessee.
  • Trillium virde (Wood Wakerobin USDA). L12.
  • Habitat. Grow Trilliums in deciduous forests predominated by oak and beech trees. Trilliums will tolerate an occasional pine tree, just don't plant them an entirely evergreen pine plantation.
  • Wisconsin: T. cernuum (statewide), T. flexipes (south half of state), T. grandiflorum (statewide), T. nivale (east edge of state), T. recurvatum (WI/IL line). T. erectum (excluded as native, cultivated only), T. undulatum (excluded as native, cultivated only).

Notes on our Trillium garden: Trillium Notes.


5 Star
Rating
Trillium Gardening (click to shop)
Book title / Comments
***** Trilliums
Excellent - a monograph on Trilliums. Complete information about the history, taxonomy, ecology and geographic distribution of Trilliums. Frederick and Roberta Case wrote the definitive book about these plants. Simply titled, "Trilliums", the book is a masterful description of all the species of Trillium, their geographic distribution, habitat, and growing conditions. Published by Timber Press. It is a must have book for the Trillium enthusiast. See our complete review at Amazon.Com

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