Purple Trillium is the most prolific Trillium in the Woodland Garden, found growing as solitary specimens and as large groupings. The species prevents the growth of other plants in that area where it grows.
The stem is an above ground portion (a flowering scape) of the underground rhizome. It is smooth, green to greenish-red and grows to 10 to 15 inches in height.
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 all Trilliums, the bracts form a whorl of 3 at the top of the stem. These are bright green with veins prominent, ovate rhombic in shape and widest at the middle.
Flowers: The flower stalk rises from the whorl of bracts thrusting the flat flower face outward and seldom upward. The 3 purple (in var. erectum) petals and the 3 green sepals are of equal length - from 1/2 to 1-1/2 inches long, but the petals are are ± 2x as wide as the sepals. The petals spread outward in the same plane as the sepals and with a slight reflexing at their tips. Like the petals, the sepals are lance shaped, widest at the base. They have prominent grooves and texture and the margins tend to twist or curl upward. Veins may have a purplish color. Veins of the petals appear as though engraved. Petal color can be widely variable from dark reddish-brown to maroon to purple to white and sometimes pale yellow in var. album. There are six stamens with thin erect filaments that vary in color, being the same or slightly different from the anther color. The anthers are erect or slightly recurving, maroon to yellowish in color and definitely yellow when the pollen is exposed. For the female flower parts the ovary is maroon to purple, no matter what the color of the petals. It is 6-angled, composed of 3 united carpels. The style is short, with 3 stigmas are dark purple and recurved with the lobes yellowish when pollen is shedding.
Fruit: The flower matures to a dark maroon seed capsule, the color of the ovary, globose to somewhat pyramidal is shape, 6-angled, and a weak aroma of fruit. This capsule is juicy and contains the seeds. The flower is ill-scented, such as wet dog smell, and has a bitter and acrid taste. Read Eloise Butler's notes below.
Varities: Two are accepted: Var. erectum where the petals are red, maroon, or dark purple; and var. album where the petals are white.
Habitat: The plant 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 and nothing else will grow in that place.
Comparisons: One of the three large Trilliums in the Garden that have an erect flower stalk - the others are the white Large Flowered Trillium and the Red Trillium, T. sculcatum. The confusing one will be the Red Trillium where the petals are said to be a darker reddish-maroon but the key differences are that the petals are less than 1.5x the sepal length, often recurved in the outer 1/2, whereas in T. erectum the sepals are as long as the petals and held in the same plane.
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, erectum, means 'erect'. 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 'wake-robin' 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.
Above: The Purple Trillium in full flower in mid May. The flower head faces outward but rarely upward.
Below: 1st photo - The anthers of the six stamens are yellow when shedding pollen. They surround a stigma of 3 recurved lobes - also yellow when pollen is shedding. The lower parts of the pistil and the filaments of the stamens are usually maroon to purple. 2nd photo - The narrow pointed sepals are as long as the petals. They tend to twist when the flower is fully opened as seen above.
Below: The emerging stems in mid April and the plant in bud. About a month elapses between emergence and full flower.
Below: 1st photo - The fruit capsule of the Purple Trillium is 6-angled. 2nd photo - After the plants die back in summer, nothing else will be growing in this spot as is shown above where the Purple Trillium are lying dormant near the Interrupted Ferns.
Notes: Purple Trillium is not indigenous to the Garden but added later. Eloise Butler first makes note of it when she recorded it in bloom on April 28, 1916. In Oct. 1918 she recorded planting the white-petaled version of the plant, T. erectum var. albidum [album], that she obtained from Gillett's Nursery in Southwick MA. From Gillett's also she obtained 12 plants of var. erectum in Oct. 1920. Martha Crone made note of it in bloom in 1939, planted it in 1945 and also listed it on her 1951 inventory of plants in the Garden at that time. It was also planted by Gardener Cary George in 1993 and 1994. It is not native to Minnesota, but to the eastern U.S. and Canada with a range westward as far as Michigan and Illinois and Ontario. 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. 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.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"