Thanks to the sharp eye and good instincts of BRAT volunteer Rhonda Benoit, a new-to-our-area invasive plant has been spotted and recorded with the State of Vermont and with the Town of Woodstock, where it was discovered.
Known by several common names such as Japanese butterbur, Fuki, Swamp Rhubarb, and Giant Coltsfoot, the imported plant hails from Asia and its exotic foliage is both the reason it's here and the reason it's a growing concern.
Petasites japonicus grows in almost any type of soil but is most enthusiastic in shady, damp soil - just what you'd expect to find along rivers, streams, ponds, and wetlands. The rhubarb-like stalks are fleshy and can grow several feet tall; the roots are pencil-thick rhizomes that spread very easily through fragmentation. Of most concern, however, are the leaves, which can grow to an impressive 4' in diameter, in dense clumps.
These leaves erupt very early in the season, small at first, along with a cabbage-like flower stalk, soon shading out any hope of native vegetation gaining a foothold.
Our riverbanks are in dire need of protection, which we saw in graphic and humbling detail in 2011 during Tropical Storm Irene. The fine mesh of native tree roots and shrub roots is vital to holding vulnerable bank soil in place, and the woody stems and trunks help slow down rising floodwaters. This allows swollen streams and raging rivers to expend more energy spreading out and settling, rather than tearing apart their banks and sending enormous loads of sediment into the water.
Rhonda Benoit and Black River Action Team Director Kelly Stettner brought the discovery to the attention of the Woodstock Conservation Commission, and Benoit will be helping the WCC do some preliminary scouting around the Ottauquechee watershed in search of more butterbur.
Stettner sent Benoit's photos of the plant to staff at the VT Department of Forests, Parks, and Recreation for identification and confirmation; the focus is now on educating the public as well as town officials and anyone involved in natural resource work in the area, such as the Native Plant Trust (formerly the New England Wildflower Society) and the Nature Conservancy, who team up to protect the Eshqua Bog in nearby Hartland VT.
The only other known population of butterbur in Vermont is in Burlington; Benoit has been in close contact with folks managing butterbur in northern Vermont, and will be staying in touch with Mike Bald of "Got Weeds?," an organization focused on the mechanical (non-chemical) management of invasive plants.
Although the butterbur plant is also known as "Giant Coltsfoot," it is not to be confused with what we know as "coltsfoot" - the more commonly-seen Tussilago farfara has much smaller leaves with edges that are more scalloped and heart-shaped. Petasites leaves are round and the edges are serrated.
While it is always frustrating to learn of a new invasive plant in the neighborhood, Stettner is excited at the opportunity for Early Detection in the case of butterbur, which can allow for a Rapid Response if enough people and organizations are working together on a management plan. "EDRR" can be very effective in managing an emerging problem species such as butterbur.
If you see what you suspect might be Petasites (butterbur) or any other plant you don't recognize, take a photo and note as precisely as possible where you spotted it; log onto VT Invasives and report it: https://vtinvasives.org/get-involved/report-it