Whorled Loosestrife is a flowering, herbaceous perennial in the Primulaceae (primrose) family. It grows in moist fields, clearings, hardwood forests, roadsides, rocky slopes, and seashores at elevations up to 1000 meters. In North Carolina it is found in a wide variety of forests and open areas, including pine savannas of the outer Coastal Plain, ranging from moist to very dry. It is common in North Carolina’s Mountains and Piedmont but uncommon in the Coastal Plain. Whorled Loosestrife is a rhizomatous plant reaching 2 to 3 feet in height with attractive whorled leaves around an upright stem. Yellow flowers with a red center form on stalks at the leaf axis. Flowers may have red margins with maroon or black streaked resin canals. This plant prefers sunny, consistently moist soils, but tolerates partial sun, drier sites, and a wide range of soil types including heavy clay. It spreads by long, shallow roots that spread along the ground and by seed, but the spread is not too vigorous. It has a limited ability to compete with other vegetation. Seeds must be sown on top of soil as they require light to germinate. Insects, Diseases, and Other Plant Problems: No serious diseases or pest problems.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 0 ft. 9 in. - 2 ft. 6 in. | Width: 1 ft. 0 in. - 2 ft. 0 in.
Maintenance
Low
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Ascending; Erect
Texture
Medium
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite; Whorled
Leaf shape
Elliptical; Lanceolate; Ovate
Leaf margin
Entire
Leaf size
3-6 inches long, 1-3 inches wide
Hairs present
Yes
Leaf detail
The leaves are in a whorled pattern along the stem in groups of 4 to 5. They are oval to lance-shaped and 2 to 4 1/2 inches long and 1/2 to 1 1/2 inches wide. The leaves are pointed at the tip with little to no stem at the base. The margins and undersides have scattered fine hairs. Opposite, linear primary leaves appear along the stems. The margins of these leaves are toothless and usually curled under. Secondary leaves are similar to the primary leaves, except they are smaller and they always linear in shape.
Flower color
Gold/Yellow; Red/Burgundy
Flower value
Long Bloom Season; Showy
Flower form
Head
Flower shape
Star
Flower size
< 1 inch
Flower detail
1/2 inch wide flowers have long stalks and arise from the leaf axils with 1 flower per axil. Flowers are star-shaped with 5 yellow petals with a reddish eye. The five stamens are united at the base by a fleshy band that is attached to the petals, giving them the appearance of an upright tube. Flowers may have a reddish margin and may have a dark-streaked resin canal (maroon or black). Flowers bloom from July to August.
Bloom time
Summer
Fruit type
Capsule
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Dry seed capsule opens to drop seeds. Fruit displays from August to October.
Stem color
Green; Red/Burgundy
Stem detail
Erect unbranched central stem is light green to red, terete or angular, and hairless. The upper half of the plant often branches, producing lateral stems similar to the central.
Wildlife & Ecology
Native status
Native
Origin
Ontario and Manitoba Canada; Eastern United States.
Distribution
Eastern Canada and United States south to North Carolina.
Wildlife value
Members of the genus Lysimachia support the following specialized bees: Macropis (Macropis) ciliata, Macropis (Macropis) patellata, and Macropis (Macropis) steironematis.
Attracts
Pollinators; Specialized Bees
Play value
Attracts Pollinators; Colorful; Easy to Grow
Food & Medicine
Fruit type
Capsule
Uses (ethnobotany)
The Cherokee used this plant to treat kidney and urinary conditions. American colonists are said to have fed the plant to pairs of oxen so that they would work together peacefully.