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U.S. Forest Service

Plant of the Week

Map of the North America showing areas colored green where the species may be found. Range map of Starflower, Trientalis borealis.

Starflower, Trientalis borealis. Starflower, Trientalis borealis. Photo by Steve Janke.

Starflower (Trientalis borealis Raf.)

By Larry Stritch

Starflower is a member of the Primrose family. The genus name Trientalis is from the Latin meaning “one third of a foot” which corresponds to the plant’s average height. The species name borealis refers to being from the north, although this plant is also distributed in the Midwest and the higher elevations of the southern Appalachian Mountains.

Starflower is a perennial herb that grows from slender, creeping rhizomes. Leaves are simple and occur in whorls of 5 to 9 at the tip of the stem. They are stalk less or on very short stalks and are entire to very finely-toothed. The flowers may occur as a single bloom or sometimes 2 to 3 blooms on slender stalks 3/4 to 2 inches long. Flowers are snow white with 5 to 9 petals and approximately 1/4 to 1/2 inch in diameter.

Starflower is one of the more common spring wildflowers in eastern North America, occurring in both deciduous and coniferous forests. Depending on latitude and elevation starflowers generally bloom from mid to late spring into early summer. Their habitat preference is open to dappled shade in moist woods but they may be found dry, sandy, acidic soils as well. Star flowers are pollinated by native bees. Starflower generally goes dormant in mid-summer with the leaves yellowing and then falling to the ground so that all that is left is the stem with 1 to 2 tiny seed capsules ripening at the tip. Seeds do not germinate before undergoing a cold stratification and do not germinate until the fall of the second year allowing seeds to be disseminated by insects. Starflowers will establish themselves in successional old fields that are adjacent to established colonies in old woods.

Many gardeners do not find starflower to be showy enough or to flower long enough for their tastes. However, if you are working in woodland shade garden it does add to the diversity of wildflowers in this type of naturalized planting. According to the New England Wildflower Society you should transplant from containers containing seed germinated plants in spring. Additionally, in late summer you can plant dormant rhizomes into an acid moist soil. These starts will easily spread around in a naturalized planting in a woodland garden. They require no maintenance once they are established. As always do not wild collect plants from public lands and only from private lands when the landowner grants permission. However, it is always best just to collect ripened seeds and not dig up rhizomes.

For More Information

PLANTS Profile - Trientalis borealis, starflower