Dotted smartweed

Description

Persicaria punctata is a species of flowering plant in the knotweed family known by the common names dotted smartweed and dotted knotweed. Persicaria punctata is native to the Americas, where it can be found in moist and wet habitat types from Canada to Argentina including the West Indies. It is an extremely variable plant. It may be annual or perennial. Persicaria punctata grows from a rhizome and produces decumbent or erect stems which may just exceed one meter (40 cm) in length. The branching stems may root at nodes that come in contact with the substrate. The lance-shaped leaves are up to 15 centimeters long and have stipules widened into bristly brown ochrea that wrap around the stems. The inflorescence is a number of branching clusters of dotted greenish flowers with white edges, sometimes tinged pink. The genus includes annual and perennial herbs with taproots or fibrous root systems, or with rhizomes or stolons. The stems are often erect but may be prostrate along the ground, and some species are prickly. The stems are self-supporting or twining and climbing. The leaves are alternately arranged, deciduous, and variously shaped. The brownish or reddish ochrea may be leathery to papery. The inflorescence may be a panicle or a spikelike or headlike arrangement of fascicles of flowers. The flower is white, greenish, reddish, pink or purple, with the tepals partially fused together along the bases. The fruit is an achene which can take a number of shapes, including a disc or a sphere. Within the family Polygonaceae, Persicaria is placed in the subfamily Polygonoideae, where the tribe Persicarieae consists of two sister genera, Bistorta and Koenigia, together with Persicaria.