Flower:

1-inch pale to medium yellow flowers, often nodding, on long slender stalks arising from leaf axils in the upper plant. Flowers have 5 petals, generally broadly oval but with a sharp, abrupt point at the tip, often with a spot of red at the petal base. In the center are 5 creamy yellow stamens.

The 5 sepals behind the flower are narrow, shorter than the petals, and streaked with 3 to 5 parallel lines. One plant has a few to many flowers.

Leaves and stem:

Leaves are up to 6 inches long and 2½ inches across, rounded at the base, tapering to a sharp point at the tip. The leaves may have fine hairs along the edge, but are otherwise smooth. The edges can be somewhat wavy. Attachment is opposite.

While the main stem is hairless, the leaf stalk and axils are conspicuously hairy, which is where this plant gets its common name.

Notes:

While there are a few other yellow loosestrife species with similar flowers, Fringed Loosestrife is easily identified by the relatively broad leaves and fringed leaf stalks. All of the Lysimachia species were formerly in the Primulaceae (Primrose) family, but have been moved to the Myrsinaceae (Myrsine) family.