Bot. Mag. 18: plate 660. 1803 ,.
Stems erect, simple or branched, (1.2–)2–10 dm, glabrous; rhizomes slender; bulblets absent. Leaves opposite; petiole 0.1–0.5(–0.9) cm, ciliate at very base near nodes, cilia 0.1–0.8 mm; blade linear to narrowly lanceolate, 3.4–9 × 0.2–0.6 cm, base cuneate, decurrent, margins entire, revolute, eciliolate, apex acute to obtuse, surfaces not punctate, glabrous; venation single-veined or obscurely pinnate. Inflorescences axillary in distal leaves, solitary flowers (or verticils). Pedicels 0.5–2.8 cm, glabrous. Flowers: sepals 5, calyx not streaked, 3.5–6 mm, glabrous, lobes lanceolate, margins thickened; petals 5, corolla yellow, sparsely streaked with brownish-violet (sometimes obscure) resin canals, rotate, 7–13 mm, lobes with margins entire (sometimes slightly erose distally), glabrous, apex apiculate, stipitate-glandular adaxially; filaments weakly connate at very base, shorter than corolla; staminodes 0.6–0.9 mm. Capsules 3.5–5 mm, not punctate, glabrous (rarely sparsely stipitate-glandular). 2n = 34.
Phenology: Flowering summer.
Habitat: Moist prairies, meadows, roadsides, springs, swamps, bogs, other wetlands
Elevation: 0-600 m
Man., Ont., Ala., Ark., D.C., Ga., Ill., Ind., Iowa, Ky., Md., Mich., Minn., Mo., N.Y., N.Dak., Ohio, Okla., Pa., S.Dak., Tenn., Va., W.Va., Wis.
Lysimachia quadriflora has been reported as an adventive from Massachusetts (B. A. Sorrie and P. Somers 1999).