History & Introduction
Previously considered a variety of the North American native Virginia jumpseed, or Persicaria virginiana, Asian jumpseed (Persicaria filiformis) is an introduced perennial herb native to Japan, the Kuril Islands, Korea, Myanmar, and Vietnam. Though it is not clear when it was introduced to North America, P. filiformis was previously cultivated here and commonly sold under the name Persicaria virginiana var. filiformis or Polygonum virginianum var. filiforme. This led to its proliferation and spread as a weed, often appearing in gardens, wetlands, and forest understories.
Studies in the 1990s – 2000s began uncovering clear genetic differences between the two species, cementing P. filiformis as an introduced species. On Long Island, documentation of P. filiformis began in 2018 in Suffolk County, according to the New York Flora Association (NYFA). NYFA does not document P. filiformis as present elsewhere in the state, although iNaturalist reports indicate presence in other regions, including throughout the extent of LIISMA (Nassau, Queens, Brooklyn, and Staten Island), as well as Manhattan, along the Hudson River, and near Buffalo and Rochester. Beginning around 2020, the spread of Asian jumpseed was documented in other Eastern states including Massachusetts, Virginia, and Ohio.
P. filiformis is likely an underreported species, due to its confusion for P. virginiana. Asian jumpseed was previously unranked in LIISMA for this reason, and is now a tier 3 species listed for containment due to dispersed presence throughout the island.
Identification & Biology
Asian jumpseed is a perennial herbaceous plant, growing up to 3.5 ft tall. It thrives in shaded habitats, and in rich moist to medium-dry soil. This includes mesic upland forests, stream bottoms, floodplain forests, and similar wetland habitats.
P. filiformis has light green obovate or elliptical leaves (widest above the middle) that alternate along the stem, and do not branch. Leaves are simple and have entire margins (smooth, not serrated edges) and may have hairs, especially on the undersides of leaves. Leaves often have a pair of brown spots near the leaf center. The brown spots on P. filiformis are often in the shape of a well-defined v-shape, whereas the brown spots on P. virginiana are less distinct if present, and will fade through the season. When comparing leaf shape of the two species, P. filiformis is ovate with a wider, less tapered, leaf tip, while P. virginiana is more elliptical and strongly tapers at the tip.
Some P. filiformis are variegated, with partly white foliage and sometimes pink spots rather than brown.
Starting in mid-summer, Asian jumpseed produces small pink flowers on the ends of stems on terminal spikes up to 1 ft in length. Plants may flower until early fall, followed by production of small hooked fruits containing seeds. Virginia jumpseed usually has greenish-white flowers, but rarely pink, so flower color alone is not enough to distinguish the two species.
Much like the native jumpseed, P. filiformis is a prolific seeder adept at spreading its seeds.It may ballistically disperse seeds up to 10 ft away from the plant, drop to the ground, or attach to people and animals passing by with its hooked fruits, to hitchhike to a new habitat.
For further resources for keying out Persicaria, use this dichotomous key for distinguishing P. virginiana and P. filiformis cultivars.
Damage & Concern
Asian jumpseed threatens a range of habitats it can grow in, including wetlands. Due to its specialized ability to disperse seeds at significant distances and hook onto animals, P. filiformis can naturalize quickly and form monocultures. Asian jumpseed threatens to outcompete native vegetation, such as its native counterpart, by shading them. It may also be hybridizing with the native jumpseed, which could alter its genetics and lead to decline of the native species. Wildlife don’t show a preference for eating Asian jumpseed, which also gives it a competitive advantage.
As with most introduced plant species, P. filiformis is diminished in its ability to support native insects. Anecdotally, most individuals of P. virginiana are said to have signs of their relationship with a native dependent insect, a native sawfly, as evidenced by small holes in leaves from the insects feeding. On the contrary, very few P. filiformis have the holes associated with the native sawfly, illustrating that it is not preferred by native insects and may consequently impact their populations and other insects that may specialize on the native jumpseed.
Management
Manual/Mechanical Control
Digging or pulling P. filiformis is said to be fairly easy. Be sure to manage before the plants set seed in fall. Asian jumpseed may have rhizomes or stolons like most Persicaria; for most effective management, remove as much of the roots and rhizomes as possible. If plants are difficult to remove by hand, managing after a rain may help.
If necessary, weed whacking or mowing large populations to prevent seed set may be useful, though more information and trials are needed to determine efficacy.
Chemical Control
Large populations of Asian jumpseed may be managed with herbicide when hand pulling is not feasible. A foliar spray of glyphosate or triclopyr consistent with the label instructions can be used. Take care when using herbicide and use non-surfactant wetland approved formulations when applying in proximity to wetlands. Always consult certified applicators and follow the herbicide label instructions.
Monitoring & Reporting
As Asian jumpseed ranks as a Tier 3 in LIISMA’s Early Detection and Rapid Response program, we urge you to please report any sightings of the plant to iMapInvasives or iNaturalist. Your observations are key to our mission, as they allow us to respond to emerging populations before becoming a larger threat to New York.
iMapInvasives is a network for invasive species reporting, allowing concerned parties like LIISMA to discern where invasive species may be popping up, or their geographic extent. Similarly, iNaturalist functions as a biodiversity reporting platform for all kinds of living things—native or non-native—and can help anyone identify and share what species are inhabiting a given area.
If you are interested in playing a bigger part in protecting our local flora and fauna, consider joining LIISMA’s Invasive Species Spotter Program! This program teaches you how to spot emerging invasive species as they arise, giving you valuable detection skills against occurrences of invasive species that were not previously on LIISMA’s radar.
References and Additional Resources
Asian jumpseed (persicaria filiformis). iNaturalist. (n.d.). https://www.inaturalist.org/taxa/914942-Persicaria-filiformis
Atha, D. (2020, October 26). American and Asian jumpseed in North America. iNaturalist. https://www.inaturalist.org/posts/43298-american-and-asian-jumpseed-in-north-america
Digital Atlas of the Virginia Flora. Digital Atlas of the Virginia Flora | Persicaria filiformis (Thunb.) Nakai. (n.d.). https://vaplantatlas.org/index.php?do=plant&plant=4678&search=Search#:~:text=The%20first%20reports%20of%20this,filiformis%20as%20a%20var.
Google. (n.d.). Key to persicaria species of North America north of Mexico 20251028.PDF. Google Drive. https://drive.google.com/file/d/1ISJEB2p2ALg4K0tdieQCeiKoj2PeQKsf/view
Knotweed update. Fairfax Gardening. (2021, October 7). https://fairfaxgardening.org/knotweed-update/
Mdinvasivesp. (2022, July 27). Don’t jump to conclusions about Asian jumpseed – Maryland invasive species council. Maryland Invasive Species Council -. https://mdinvasives.org/iotm/may-2022/#:~:text=Virginia%20knotweed%20or%20jumpseed%20(Persicaria,the%20Asian’s%20reddish%2Dpink%20flowers.
Persicaria filiformis. Persicaria filiformis – Species Page – NYFA: New York Flora Atlas. (n.d.). https://newyork.plantatlas.usf.edu/plant.aspx?id=7822
Virginia knotweed (jumpseed). Missouri Department of Conservation. (n.d.). https://mdc.mo.gov/discover-nature/field-guide/virginia-knotweed-jumpseed#:~:text=Virginia%20knotweed%2C%20or%20jumpseed%2C%20is,with%20appressed%2C%20often%20woolly%20hairs.
