Starflower is a herbacous woodland and wetland plant rising on erect slender stems to an average height of 4 inches (range is 2 to 8 inches).
Leaves are alternate but concentrated into a whorl at the top of the stem. These vary in length, are up to 4 inches long, and vary in shape from lanceolate (widest above the middle) to elliptic to spatula shape. Tips are pointed, bases wedge shape, the margins usually entire, and no surface hair. The vein pattern is pinnate (one central vein with lateral branching). There may be a short stalk or none. Lower on the stem there may be a few very small linear leaves or sometimes small scale like leaves.
The inflorescence is a stalked flower rising from the upper leaf axil. Plants may have from 1 to usually no more than 3 flowers.
Flowers: The snow white flowers usually have 7 petals (can be 5 to 9) that have pointed lobes spreading upward and outward forming the star design the plant is named for. The petals overlap near the base. Flower are stalked, stalks rising from a leaf axil. The stalks are shorter than the leaves are long. The calyx of the flower is a very short tube, with the green sepals much longer than the tube, but shorter than the petals. The sepals appear between the petals, so are usually one less in number than the petals. They are long and thin. The stamens have long white filaments, with yellowish anthers, and are the same number as the petals. The ovary is globose, 5-celled, with a single style.
Seed: Pollination is usually by bees and fertile flowers produce a globose 5-valved seed capsule that splits when seeds are mature. Seeds are very small and do not germinate until the 2nd year as they need a cold moist period followed by a warm moist period and then another cold moist period.
Habitat: Starflower has a slender rhizomatous root system which grows from a tuber at the plant base. The plant spreads when the rhizomes elongate and form a new tuber at the tips. The new tuber has root and shoot buds, allowing the rhizome to die, but creating a new plant. It can be found in a variety of forest soils ranging from dry to wet, and in bogs and heaths where the soil is acidic. Dappled shade is best, full sun only if soils are constantly moist.
Names: In earlier years of the 20th century our species of Starflower was sometimes classified as Trientalis americana. That became a synonym for T. borealis, all in the Primulaceae family. Now another botanical name change has occurred based on molecular data. A number of printed references may not yet note this, including Flora of North America as the change in nomenclature was made after FNA went to press; the University of Minnesota Herbarium notes: "see Willdenowia 39: 51. 2009". The former scientific name for this species was Trientalis borealis, where Trientalis was Latin for "one-third of a foot," referring to the average height of the plant.
The new assignment places Starflower into the Myrsinaceae family and into the genus Lysimachia, which is from the Greek for either king Lysimachus or from lysis meaning "a release from" and mache meaning "strife". The legend is that Lysimachus, king of Sicily, was walking through a field. A bull chased him. He grabbed a loosestrife plant, waved it in front of the bull and it calmed the bull. In general then, both the common and the generic name refers to a supposed power to soothe animals or "loose" them of their "strife". All species of the Myrsinaceae found in Minnesota are now in the Lysimachia genus. The species name, borealis, is also from the Latin meaning "of the north", referring to the geographic area where the plant is concentrated.
The author names for the plant classification are as follows: The first to classify was ‘Raf.’ which refers to Constantine Samuel Rafinesque, (1783-1840), European polymath who traveled in the United States, lived here many years, collected specimens, and published over 6,700 binomial names for plants. He applied to be botanist on the Lewis & Clark expedition but Jefferson turned him down in favor of training Lewis to act as botanist and saving the expense of another person. His work is recognized but amended by two people responsible for the nomenclature change: ‘Anderb.’ refers to Arne A. Anderberg, (b. 1954), Swedish botanist who published several papers on the Lysimachia (Myrsinaceae). Co-author on those papers was 'U.Manns' which refers to Swedish Botanist, Ulrika Manns (B. 1965).
Comparisons: In some areas Starflower overlaps with and could be confused with Indian Cucumber Root, Medeola virginiana, when the plants are not in flower. The flowers are very different. In Cucumber Root the leaves have parallel veins (running from the base, not from a central vein). Like Starflower, it also has leaves in a whorl atop the stem, but while young plants have only one whorl, like Starflower, older plants usually have two whorls. Indian Cucumber Root has not been found in Minnesota but is known in Wisconsin.
Other types of Starflower: There are two other species of Starflower that before the reclassification were named Trientalis europaea and T. latifolia. These will have some geographic overlap in certain areas with L. borealis - europaea has flower stalks longer than the leaves and lower leaves gradually become smaller. In our species and in latifolia the lower leaves abruptly become smaller. The latter has pinkish to more lavender colored flowers. Neither of these other species are known in Minnesota.
Above: A solitary whorl of leaves tops the stem, with the flowers rising from leaf axils. Note the reduced leaf on the stem. Drawing courtesy of Flora of North America.
Below: 1st photo - This flower has the typical 7 petals and 7 stamens. Tips of the sepals just emerge between the petals. 2nd photo - Leaves in the whorl are of different sizes.
Below: 1st photo - The calyx is very small with much longer sepals, numbering six here and appearing between the petals. 2nd photo - The very small lower stem leaf. 3rd photo - the 5-valved seed capsule maturing.
Below: A group of plants with Marsh Fern among them.
Notes: Starflower is not indigenous to the Garden but was introduced by Eloise Butler in 1908 with plants from Osceola, WI. Curator Martha Crone also planted the species in 1935, with plants from the Gunflint Trail in Northern Minnesota, using the name Trientalis americana, and again in 1947 and '48.'
L. borealis is found in the eastern section of North America, in states east of the Mississippi River excepting the Gulf Coast area, and in Canada east of Alberta. Within Minnesota distribution is concentrated in the 2/3rds of the state that lie north and east of a diagonal line drawn from Fillmore County in the SE to Ottertail and Norman County in the NW.
Fourteen species of Lysimachia are of record in Minnesota per the U of M Herbarium as of 2018; several have not been collected in recent decades. Ten are still listed currently by the DNR on their plant surveys. Of those nine are native, one is introduced. The species of Lysimachia of record in the Garden, current and historical, are: Starflower, L. borealis; Fringed Loosestrife, Lysimachia ciliata; Moneywort, L. nummularia (the introduced species); Prairie Loosestrife, Lysimachia quadriflora; Whorled Loosestrife, L. quadrifolia; Swamp Candles, Lysimachia terrestis; Tufted Loosestrife, Lysimachia thyrsiflora; Garden Loosestrife, Lysimachia vulgaris.
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"