Persicaria longiseta, commonly known as Oriental lady’s thumb or Asiatic smartweed, is an annual herb that originates from moist areas, such as riverbanks and wetlands, in Asia. It has been introduced to North America and Europe, where it is often considered invasive. This plant typically features stems that are 12 to 31 inches long and lance-shaped leaves that can reach up to 3 inches in length. The flowers are small, pink to white, and arranged in a dense, elongated cluster, blooming from summer to early fall. The flowers are not particularly showy, but they can add a subtle charm to the plant’s overall appearance.

Oriental lady’s thumb is valued for its rapid growth and adaptability to various soil conditions, which can be useful for quickly covering bare areas. However, due to its invasive nature, it is not commonly recommended for cultivation. In areas where it is not invasive, it may be used as ground cover or for erosion control. It thrives in moist, fertile soils with good drainage and can tolerate both full sun and partial shade. There are no popular garden cultivars due to its invasive tendencies. Gardeners should be cautious as it can spread aggressively through its rhizomes and seeds, potentially outcompeting native vegetation.CC BY-SA 4.0