Incised Fumewort

by Ann McMillan (Master Gardener)

Henrico is once again on the map — sadly, it’s not a map we want to be on.


EDDMapS ( and its apps) enables citizen reporting of invasive species, validates reports, and creates maps down to the individual population level. It runs out of the University of Georgia Center for Invasive Species and Ecosystem Health. Comparing sites and dates of reporting, the user can get a glimpse of how these undesirables spread.


My addition to the map is incised fumewort — Corydalis incisa. The Maryland Invasive Species Council (MISC) highlighted this plant in May 2017 ( In the Richmond area, its first mapped appearance dates to the same spring, south of the James River opposite Maymont.


The MISC describes a “biennial, shade-tolerant forb in the poppy family.” It suspects unwitting transportation of the plants to the U.S., where it was first reported in 2005 along the Bronx River in New York.


It further describes “a 3″-24″ biennial forb with deeply cut, glabrous leaves, and purple flowers. The first year plant shows few leaves, which grow from a small tuber. The second year plant is upright with numerous branched leaves. Leaves are divided into three leaflets, with those leaflets further divided into threes, or even divided again into threes. They are 1.5″-5″ inches long and wide, on 2″-8″ leaf stalks, with the smallest leaves near the inflorescence. The purple flowers (rarely white) are tubular, about 1/2″ long with reduced, irregularly cleft sepals. The petals touch each other but are not fused. Flowers occur in elongated clusters up to 4″ long, with 10-16 flowers per raceme. Green oblong seed capsules hang from the ends of the flower stalks; they are less than 1″ long and look like tiny, short green beans. Incised fumewort has seed capsules that open explosively when the seeds are mature, and can launch the small black seeds up to 10 feet.”


Per MISC, as of 2017, bloom time for incised fumewort is May; I first spotted its blooms in mid-March along Deep Run Creek near my home. I hadn’t noticed it before, and perhaps it was only in its first flowering season. But it was already taking over, crowding out natives like Virginia springbeauty (Claytonia virginica) and golden ragwort (Packera aurea). To quote the Maryland Council again, incised fumewort “can grow very densely in monotypic stands along riverbanks.” This is what I am seeing.


In 2017, this invasive was deemed “an early detection species that may still be eradicated by a region-wide rapid response.”


Trying to mount my own rapid response, I spent a few hours on several different occasions removing plants. I may have taken out hundreds of plants, but there were thousands. Meanwhile, the seedpods were maturing, and on my last outing to pull up plants I could hear the seeds releasing onto the ground.


I retreated, hoping to return at a more propitious time, and with reinforcements.