Mile-a-minute (Persicaria perfoliata)

Key Identification Features

• Triangular leaves

• Blue berries

• Sharp, recarved barbs

• Ocreae surrounding stem

Description

Mile-a-minute is a fast-growing, barbed vine that smothers other plants by growing over them. It is a herbaceous, annual vine that grows equilateral triangles that are 5-7 cm long and 5-9 cm wide.  Two notable features are the ocreae (sheaths) surrounding nodes and sharp, recarved barbs along its stems. These recurved barbs are used by the plant to climb surfaces quickly, growing up to 6 inches a day. Its flowers produce blue-colored berries that are eaten and transported by birds.

Native Range

Mile-a-minute is native to India and Eastern Asia but was accidentally introduced through a contaminated Holly seed brought into Pennsylvania in the 1930s. In its native range, it is used to feed cattle, prevent soil erosion, and can be used as mulch.

Habitat and Dispersion

Mile-a-minute is a very versatile plant but prefers disturbed areas, or to be in open areas such as along streams, woods, roads, cultivated fields, or wetlands. It prefers wet soils but can grow in dry soils as well. They disperse through seed production and are self-fertile plants. Seeds can be viable for up to 6 years and germinate at different times of the year.

Best Management Practices

Depending on the severity level of the site, there are multiple options. One is biological control, by using Rhinocominus latipes, which is a 2 mm long weevil that lays eggs on the plant, and their larvae consumed the mile-a-minute. This stress usually limits the plant’s ability to produce seeds. Manual pulling of the plant is also effective when done consistently for many years when done early in the spring before they seed. Foliar spray is also an effective control, but since they grow on top of other plants, there is the risk of damaging native plants that are desirable.

Additional Resources

NYSDEC Species Info

USDA

Invasive.org