Lysimachia quadriflora Sims
Family - Primulaceae
Stems - To +/-1m tall, erect, from fleshy rhizomes, herbaceous, branching, glabrous, 4-angled, slightly winged in upper portions by decurrent leaf tissue.
Leaves - Opposite, decussate, linear, sessile, entire, deep shiny green, with single prominent midrib, acute, glabrous, to +/-13cm long, +/-7mm broad. Margins revolute and often with a few cilia near base.
Inflorescence - Axillary pedicillate flowers near the tips of the stems. The internodes are very short in the upper portions of the plant and create a whorled appearance. Pedicels glabrous, to 2.5cm long. Flowers nodding.
Flowers - Corolla yellow, to 2.5cm broad, 4-lobed. Lobes rotund to ovate, apiculate, slightly lacerate to erose on apical margins, glabrous externally, densely glandular near base internally. Corolla tube very short, to 2mm long. Stamens 5, erect, adnate at apex of corolla tube, opposite the corolla lobes. Filaments compressed slightly, white, glandular pubescent, to 4mm long. Anthers orange-brown, 2.5-3mm long. Style whitish green, glabrous, 5mm long. Ovary superior, subglobose, green, glabrous, 5-valved, 1.2mm in diameter. Placentation free-central. Locules (seeds) many. Sepals 5, spreading, to 7mm long, 2.5mm broad, glabrous, ovate-lanceolate, entire, green, acute to acuminate.
Flowering - June - August.
Habitat - Stream banks, swampy meadows, wet thickets.
Origin - Native to U.S.
Other info. - This species can be found in the central portions of Missouri. The plant is easy to ID in the field because of its thin, opposite leaves, its falsely-whorled flowers, and the wet habitat it prefers. L. quadriflora also prefers calcareous soils. The flowers can sometimes be white in color.
Photographs taken along the shores of the Current River, Shannon County, MO., 7-6-03.