The stem is an above ground portion (a flowering scape) of the underground rhizome. It is smooth, green to greenish-purple and 8 to 14 inches in height. Purplish tones are typically near the base.
Leaves: In the true trilliums the leaf like parts are actually floral bracts just below the flower base. They are of course much larger than the normal small bracts of most plants, but they are equipped to fulfill the function of a leaf. These are broadly ovate, the largest of the Garden's Trilliums, with pointed tips and prominent veins. Always a whorl of three atop the stalk, they attach directly to the stalk (sessile) or have very short stalks.
Flowers: The large white flowers (2+ inches wide) are funnel shape at the base, on a mostly erect 2 to 3 inch stalk (pedicle), facing upward and outward above the large bracts giving a total height of up to 16 inches. The 3 white petals are elliptical with pointed tips, recurving above the middle section. The petals are longer than the 3 green sepals behind the petals with the sepals placed so as to appear between the petals. The petals have wavy margins and overlap toward their bases forming a tube that hides the ovary of the flower. They also show prominent veining and turn pink with age. The sepals are lanceolate in shape, spreading and sometimes with maroon streaks. Stamens number six and the anthers are thin, pale yellow to strongly yellow when pollen is ripe and recurved slightly. The stamen filaments are white and shorter than the anthers. The female ovary is white to greenish-white, composed of 3 united carpels, angled on the joint lines. The style is short with 3 erect stigmas with the tip of one spreading away from the other two.
Fruit: At maturity the fruit is a pale green berry about 1/2 inch wide with 3 angles that appear as 6, resembling the ovary. It is pulpy and moist but not juicy and contains the seeds. Read Eloise Butler's notes below.
Trilliums are tedious to start from seed as they must have a cold moist period, followed by a warm moist period, followed by another cold moist period, each period of at least 60 to 90 days. Planted in soil, they will thus germinate in the 2nd Spring. Then they will take 3 to 5 years before they flower. Former Garden Curator Martha Crone wrote about a quicker method to produce more plants.
"Rather than wait for this slow process I find a much faster method is to transplant individual plants and at the same time injure the corm. The following year many stalks are produced on this single corm. This method has produced 25 blooming stalks from one corm. Following their first blooming they should be separated and planted individually." from The Fringed Gentian™, Vol. 6 No. 1
Habitat: Large-flowered Trillium grows from thick rhizomes and will spread into a nice clump overtime if left undisturbed. Like most Trilliums it will grow best in well drained soil in light full shade or dappled sun under the tree canopy. The plant dies back to dormancy by mid summer. The plant is unfortunately, subject to invasion by mycoplasmas which cause deformations such as multiple bracts, odd colorations and doubling of petals.
NOTE: Picking the flower will cause the plant to stop flowering for several years.
Names: The genus name Trillium, is derived from the Latin trilix, meaning 'triple' and referring to the flowers having parts of three. The species grandiflorum, means 'large flowered'.
The author names for the plant classification are: ‘Michx.’ refers to Andre Michaux (1746-1802), French botanist who made many exploring expeditions in the U.S. collecting and cataloging many species. Two important works of his are the Histoire des chênes de l'Amérique septentrionale (1801 - Oaks of North America), and the Flora Boreali-Americana (2 vols., 1803, published posthumously, containing the description of this species). His son Francois, traveled with him and the father’s notes were later used for the 3-volume North American Sylva. Michaux's descriptions were modified in 1805 by ‘Salisb.’, which is Richard Anthony Salisbury, (1761-1829), British botanist who developed an extensive garden and published many taxonomic revisions, but much of his work was plagiarized and discredited, however some of his work has been reinstated such as here.
The alternate common name of 'wake-robin,' of English origin, has been applied to many Trillium species, apparently because the Trilliums tend to bloom during the time that the robins are arriving in the northern latitudes.
New Family: There is a movement among botanists to segregate the Trilliums and a few other genera out of the Liliaceae Family and into the Melanthiaceae. The U of M Herbarium has made this change on their Minnesota checklist but Flora of North America has not yet published this.
Comparisons: One of the two large Trilliums in the Garden that have an erect flower stalk (the other the Purple Trillium).
Above: 1st photo: Key characteristics of this plant are: Ovate green bracts in a whorl of 3, large showy white flower on a 2 to 3 inch stalk held above the bracts, spreading petals that form a tube at their base, veined and longer than the green sepals. 2nd photo: The stems are flowering scapes, rising directly from the rhizome, often purplish at the base, green further up, with purplish-green coloration on longitudinal lines.
Below: The 3 green sepals spread a bit and slightly reflex when the flower opens. They are placed so as to appear between the petals when viewed from the front of the flower.
Below: 1st photo: The petals take on a pink tinge as they age. 2nd photo: The shape of the ovary is clearly visible in this maturing flower.
Below: The fruit is a pale green berry about 1/2 inch wide with 3 angles that appear as 6 due to the joint lines between the three carpels of the flower. It is pulpy but not juicy and contains the seeds. Shown here in the ripening stage.
Below: During the Garden curatorship of Martha Crone there was an extensive bed of Large-flowered Trillium in the Woodland Garden as this image of April 29, 1952 illustrates. Today there are many groupings of this species at various places in the Woodland Garden, but none with the extent of this former group on the West hillside which is approximately where Eloise Butler first planted the species.
Notes: Large-flowered Trillium is not indigenous to the Garden area. Eloise Butler's records show that she first obtained plants of this species in May 1908 from Zumbra Heights (on the shore on Lake Minnetonka west of the city) and again on June 4, 1909 from Hawkins, WI; more from Horsford's Nursery in Charlotte, Vermont, in 1914; on Oct. 7, 1916 - 50 plants from Horsford's which she planted at the "base of the West Hillside"; 12 from Gillett's Nursery in Southwick MN in 1920; additional plants on June 2, 1924 from Hillman, MN; additional plants on May 20, 1928 from the Mille Lacs Lake area in Minnesota; on Oct. 1, 1928 from Strands Nursery in Taylor's Falls. Martha Crone planted the species numerous times: 1933, '34, '35, '46, '47, '48, '49, '51, '52, '56, '57 and even seeds in '39, 43, '53, and '54. She nourished the extensive growth of this plant as the above photo clearly indicates. Susan Wilkins has been the last Curator to plant, adding 20 in 2020.
It is native mainly to east-central Minnesota which is the plant's most western approach in the U.S. In Canada it appears from Ontario eastward. Four Trilliums are considered native to Minnesota: T. cernuum, T. flexipes, T. grandiflorum and T. nivale.
Bloom dates: Both Gardeners Ken Avery and Cary George kept records of these early bloomers. Ken’s list noted that his earliest date was April 16, and the latest May 22. In Cary’s time it bloomed six days earlier on April 10, 1981.
Eloise Butler wrote: "In some favored places about Lake Minnetonka may be seen during May profuse growths of the beautiful Large-flowered Trillium. So highly is this plant esteemed by the English that they have imported large quantities of it from this country for plantations in their private parks. The petals, at first pearly white, turn pink in age, as does the seed vessel.
Trilliums are closely related to the lilies. All have a thick underground stem, bearing a single aerial stem, which supports a whorl of three large leaves varying somewhat in size and shape in different species. Above the leaf whorl arises the lovely flower, with or without a stalk; erect or drooping; white, red, purple or pink striped, according to the species. The flower is also on the plan of three green sepals, three colored petals, six stamens in two rows and one pistil made up of three united carpels. The name trillium probably comes from the three leaves. The plant has a number of local names - wake robin, bath flower and “way down east.” Published May 21, 1911, Minneapolis Sunday Tribune. Read article.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"