Marsh Ecosystem-Scarlet Smartweed

Scarlet Smartweed

Order: Caryophyllales

Family: Polygonaceae

Genus: Persicaria

Species: P. coccinea

General Characteristics: This native perennial plant is about 2–3' tall and sparingly branched. The central stem is more or less erect (for terrestrial plants), swelling somewhat at the nodes where the leaf-sheaths wrap around the stem. These nodes can be brownish and hairy, but are never bristly at the edges. The alternate leaves are up to 8" long and 3" across, and have short petioles. They are usually lanceolate or ovate-lanceolate. Their margins are smooth, although they may curl up and down or twist about. The surface of the leaves (upper and lower) can be either hairless, or have appressed silvery hairs, depending on the local ecotype. The midvein on the underside of each leaf is quite prominent. There are 1 or 2 terminal racemes of flowers at the apex of the central stem. The flowering stalks are quite hairy and often brownish in appearance. The cylindrical racemes are about 2-3" long and densely crowded with flowers. Each flower is about 1/6" across, consisting of 5 petal-like sepals, 5 stamens, and a divided white stigma. The sepals of these flowers are rosy pink or scarlet, and rather showy. The blooming period can occur from mid-summer to early fall, and lasts about 1-2 months for a colony of plants. There is no noticeable floral scent. The black seeds are oval or orbicular in shape, with a shiny surface that may be slightly granular. The root system produces long rhizomes, which enable this plant to form sizable colonies. Habitats include moist meadows or prairies in areas prone to flooding; marshes, swamps, and borders of ponds and lakes, including areas with shallow water; and ditches along roads and railroads. This is primarily a wetland plant that is found in the sloughs of prairies, sometimes growing beside Iris virginica shrevei (Blue Flag Iris).

Special Adaptations: The flowers attract many kinds of insects, especially flies, wasps, and small bees. Other flower visitors include small butterflies, skippers, and beetles. These insects seek nectar primarily. The caterpillars of the moths Lithacodia synochitis (Black-Dotted Lithacodia) and Lithacodia carneola (Pink-Barred Lithacodia) feed on the foliage, while the caterpillars of the butterfly Strymon melinus (Gray Hairstreak) eats the flowers and buds. The seeds of smartweeds are a popular source of food to many kinds of birds, especially those that inhabit wetlands.