The stem is an above ground portion (a flowering scape) of the underground rhizome. It is smooth, green to greenish-purple and 8 to 16 inches in height. Purplish color tones are most prominent near the base.
Leaves: In the true trilliums the leaf like parts are actually bracts just below the flower base. They are of course much larger than the normal bract that you see, but they are equipped to fulfill the function of a leaf. Like the other Trilliums, the bracts are in a whorl of 3 atop the scape. These bracts are stalkless or with a barely noticeable stalk, bright green in color, oval to rhombic in shape, with prominent veining and a pointed tip.
Flower: Nodding Trillium has 1-1/2 inch wide white flowers with three lance-like petals and 3 green spreading sepals, which are slightly shorter than the petals or of equal length. The petals are reflexed and extend backward behind the plane of the sepal bases by more than half their length which distinguishes it from Drooping Trillium where do not reflex nearly that much. They can be pale pink in color, but not frequently. Petals are also very thin and the veining is not conspicuous. There are six stamens with slender white filaments. The anthers are straight, not more than 1/4 inch long and range in color from pale lavender to pink to gray. Female flower parts are white to pinkish, becoming yellowish at maturity. The ovary consists of 3 united carpels, widest near the base, strongly 6-angled. The style is short, with a thick base and has 3 stigmas tapering to recurved tips. The flower is solitary and usually nodding beneath the bracts on a 1/2 to 2 inch long stalk (pedicle).
Fruit: The flower matures to a dark red ovoid shaped, 6-angled fleshy seed capsule that has an aroma of fruit. Read Eloise Butler's notes below in the bottom page section. 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.
Habitat: Nodding Trillium grows from a thick rhizome which will slowly spread to create a clump of plants if left undisturbed. Plant it in light shade to dappled shade beneath the tree canopy in moist but well drained soil. The plant dies back to dormancy by mid summer.
Names: The genus name Trillium, is derived from the Latin trilix, meaning 'triple' and referring to the flowers having parts of three. The species name, cernuum, means 'drooping' or 'nodding'. The author name for the plant classification - 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. The alternate common name of Whip-poor-will flower has been applied to many Trillium species, apparently because the Trilliums tend to bloom during the time that Whip-poor-will birds do a lot of singing. The same applies to the name 'wake-robin' which has been appended to many Trilliums also - it is primarily a British term - 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.
Compare to Drooping Trillium where the flower droops on its pedicle but remains above the bracts and the petals have prominent veining.
Above: Note the characteristic hanging (nodding) flower on a short stalk beneath the bracts; the lance-like petals and green sepals of almost equal length. Note also the pointed tips to the widely oval green bracts. Flowers bloom in late April to mid-May depending on the season.
Below: While the open flower nods under the bracts, the flower bud is, at first, erect
Below: 1st photo - Several plants showing the drooping flower. 2nd photo - The white petals reflex and extend behind the plane of the sepal bases by more than half their length. The curved tip of a style is visible. 3rd photo - Like most large Trilliums, the lower portion of the stem takes on reddish colors while the upper is greenish.
Notes: Nodding Trillium is indigenous to the Garden. Eloise Butler catalogued it on May 25, 1907. It was included on Martha Crone's 1951 Garden Census; she had planted it in 1946. Gardener Cary George also planted it in 1993 and 1994. The plant is native to Minnesota. The reported distribution by county is widely scattered throughout the state with most concentration in the northern half and with most absences in the southern 1/3 which is somewhat opposite of the Drooping Trillium, T. flexipes, which is concentrated in the SE section. In North America it is found from Minnesota, Wisconsin and Alberta eastward to the coast, but not south of the old Mason-Dixon line. Four Trilliums are considered native to Minnesota: T. cernuum, T. flexipes, T. grandiflorum and T. nivale.
Eloise Butler wrote: 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.
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"