We encourage VMN volunteers to be on the lookout for emerging invasive species. Early detection helps make a rapid response more possible, so that the spread of these new invasives can be stopped or slowed. In recent months, VMN volunteers have reported work to curtail the spread of an emerging invasive plant, Incised Fumewort (Corydalis incisa) at two different locations.

Incised Fumewort, a shade-tolerant biennial native to eastern Asia, was first reported as naturalized in North America in 2005. The species has the ability to spread rapidly, possibly more than doubling a patch in one year. Seeds are ballistically ejected up to ten feet and can be further dispersed by ants and water. While Incised Fumewort is not yet on the official Virginia Invasive Plant Species List, agencies and land managers such as the Virginia Department of Forestry, National Park Service - National Capital Region, the Fairfax County Park Authority, and Virginia Cooperative Extension have indicated that the species is invasive and therefore likely to cause ecological or economic harm or harm to human health.

An Albemarle County Parks and Recreation employee called and the Rivanna Master Naturalists answered her plea for help to remove C. incisa from a flooded area in Darden Towe Park. Working together, the VMN volunteers removed ALL the C. incisa in this area, making room for the native Corydalis flavula, Viola sororia, Erythronium americanum, and Claytonia virginica to fluorish in the springtime and for Impatiens capensis in the late summer!
--Contributed by Ruth Stornetta, VMN Rivanna Chapter via the Rivanna Chapter newsletter
--Contributed by Ruth Stornetta, VMN Rivanna Chapter via the Rivanna Chapter newsletter

Pockets of Incised Fumewort have been documented in the James River drainage since 2017, primarily in Richmond City and upstream. On March 4, 2024, large, dense patches of Incised Fumewort were observed in and along a narrow strip of privately owned woods between a senior living community in Powhatan Courthouse, Virginia and Powhatan County’s Fighting Creek Park and Trail. A few flowers were blooming and some seedpods had already formed.
Based on its location, this fumewort population has the potential to rapidly spread C. incisa into Fighting Creek Park and Trail, Fighting Creek, downstream via Rocky Ford toward a DWR Wildlife Management Area, the Appomattox River drainage, and further into the lower James River drainage. Multiple drain pipes from the neighborhood discharge within the fumewort patches and combine with water running off the alley to provide an easy conduit for seed spread. Flags marking location of plants demonstrate that water is already carrying seeds along the washes toward and along the edge of the major wash at the bottom of the hill. With the steep slope of the hill and the volume of moving water, seeds can rapidly spread into the watershed via the extensive floodplain along the bottom.
Before developing plans for a rapid response to control and hopefully stop the spread of the fumewort population, members of the James River Master Naturalist Chapter talked with landowners, neighbors, park personnel, botanists, potential stakeholders downstream, and local and state professionals experienced with fumewort challenges. Dr. John Hayden, Professor of Biology, botanist, and Curator of the Herbarium at University of Richmond, visited the site on March 10, and collected a voucher specimen. Kevin Heffernan, DCR Natural Heritage Program Stewardship Biologist, as well as a Virginia Tech weed scientist (via local Extension offices) were also consulted.
The full spread of fumewort at the site, including outlying first and second year plants, measured approximately 38’ X 60’, or more than 2,000 square feet.
In hopes of quickly containing the spread in the short-term and hopefully eliminating the population in the long-term, a rapid response was deemed necessary. A plan was discussed to include covering large patches with cardboard secured with purchased mulch and downed branches, and mechanically digging, pulling, and/or hoeing smaller outlying patches and newly emerging seedlings. On March 17, the initial plan was implemented by two volunteers. To the extent possible, plants were bagged or otherwise covered by cardboard and/or mulch.
Since March 17, the site has been monitored about 3 days a week as time and weather permitted to continue hoeing, pulling, or digging plants and removing by hand and bagging developing flowers and seedpods. The entire involved area of the hillside is scoured several times a week to remove as many emerging plants as possible based on available volunteers, prioritizing the most mature plants. Unfortunately, when flower stalks are pulled by hand from second year plants, the plants have the ability to rapidly reemerge, seemingly within a few days, and bloom almost at ground level, making control extremely difficult.
As of April 17, 2024, we are not aware of any seed pods reaching maturity and ejecting seeds, but anticipate that the site will need to be monitored throughout the winter and until all foliage is dormant the following summer for at least 5 years as missed or dormant seeds continue to produce plants. Seedlings have even been found 3 or more feet above the duff growing in crevices of large tree trunks, possibly ejected from pods and/or carried and deposited by ants. In addition, the surrounding area, including streambanks, will need to be scoured for years for plants that may have escaped the site.
--Contributed by Suzie Leslie, VMN James River Chapter
Based on its location, this fumewort population has the potential to rapidly spread C. incisa into Fighting Creek Park and Trail, Fighting Creek, downstream via Rocky Ford toward a DWR Wildlife Management Area, the Appomattox River drainage, and further into the lower James River drainage. Multiple drain pipes from the neighborhood discharge within the fumewort patches and combine with water running off the alley to provide an easy conduit for seed spread. Flags marking location of plants demonstrate that water is already carrying seeds along the washes toward and along the edge of the major wash at the bottom of the hill. With the steep slope of the hill and the volume of moving water, seeds can rapidly spread into the watershed via the extensive floodplain along the bottom.
Before developing plans for a rapid response to control and hopefully stop the spread of the fumewort population, members of the James River Master Naturalist Chapter talked with landowners, neighbors, park personnel, botanists, potential stakeholders downstream, and local and state professionals experienced with fumewort challenges. Dr. John Hayden, Professor of Biology, botanist, and Curator of the Herbarium at University of Richmond, visited the site on March 10, and collected a voucher specimen. Kevin Heffernan, DCR Natural Heritage Program Stewardship Biologist, as well as a Virginia Tech weed scientist (via local Extension offices) were also consulted.
The full spread of fumewort at the site, including outlying first and second year plants, measured approximately 38’ X 60’, or more than 2,000 square feet.
In hopes of quickly containing the spread in the short-term and hopefully eliminating the population in the long-term, a rapid response was deemed necessary. A plan was discussed to include covering large patches with cardboard secured with purchased mulch and downed branches, and mechanically digging, pulling, and/or hoeing smaller outlying patches and newly emerging seedlings. On March 17, the initial plan was implemented by two volunteers. To the extent possible, plants were bagged or otherwise covered by cardboard and/or mulch.
Since March 17, the site has been monitored about 3 days a week as time and weather permitted to continue hoeing, pulling, or digging plants and removing by hand and bagging developing flowers and seedpods. The entire involved area of the hillside is scoured several times a week to remove as many emerging plants as possible based on available volunteers, prioritizing the most mature plants. Unfortunately, when flower stalks are pulled by hand from second year plants, the plants have the ability to rapidly reemerge, seemingly within a few days, and bloom almost at ground level, making control extremely difficult.
As of April 17, 2024, we are not aware of any seed pods reaching maturity and ejecting seeds, but anticipate that the site will need to be monitored throughout the winter and until all foliage is dormant the following summer for at least 5 years as missed or dormant seeds continue to produce plants. Seedlings have even been found 3 or more feet above the duff growing in crevices of large tree trunks, possibly ejected from pods and/or carried and deposited by ants. In addition, the surrounding area, including streambanks, will need to be scoured for years for plants that may have escaped the site.
--Contributed by Suzie Leslie, VMN James River Chapter