Botanists with the Vermont Fish and Wildlife Department have rediscovered a population of false mermaid-weed (Floerkea proserpinacoides)—not seen in Vermont since 1916 and believed to be locally extinct—along a stream in Addison County.
“We’ve been searching for this plant for years,” said Grace Glynn, Botanist at the Vermont Fish and Wildlife Department. “We knew of two original sites where false mermaid-weed existed in the 1800s and early 1900s but is absent today. We think the species was lost from those sites perhaps due to development, invasive species, or extreme flood events. So, we’re thrilled to know that false mermaid-weed has persisted along a separate stream all this time.”
False mermaid-weed is a delicate annual herb with small, greenish flowers, typically found in floodplain forests along low-gradient rivers. The species is Vermont’s only plant that is both a spring ephemeral and an annual. Spring ephemeral perennials like trout lily and spring beauty spend much of the year as dormant bulbs after flowering and leafing out in the spring. In contrast, individual false mermaid-weed plants die after producing seeds by early June. Each winter, a new flush of seeds germinate under the snow.
A regionally rare species, false mermaid-weed is listed as endangered in Connecticut and historically known from only one population in Massachusetts.
“It’s a remarkable rediscovery, comparable to the recent rediscovery of small whorled pogonia after a similar lapse of time,” said Art Gilman, Research Botanist at the University of Vermont’s Pringle Herbarium. “It is especially interesting because the species is hardly known to any Vermont botanist—it is unassuming and easily overlooked. However, false mermaid-weed adds a significant element to our biodiversity as a member of a family that does not have any other representatives in the state.”
Glynn says the population was found earlier this month thanks to Molly Parren, a Turtle Technician at the Vermont Fish and Wildlife Department. Parren was surveying wood turtle habitat in Addison County when she noticed a species of very rare wild garlic (Allium canadense var. canadense) growing along the stream.
“Molly sent me a photo of the wild garlic, and a small plant in the corner of the frame caught my eye. I couldn’t believe it, but there was the false mermaid-weed,” said Glynn. “I immediately called Molly and said, ‘you won’t believe what you just accidentally found!’”
Glynn returned to the site the next day and found hundreds of false mermaid-weed plants growing on a rich floodplain terrace.
“We’re very fortunate that we were able to get landowner permission to survey this false mermaid-weed population,” said Glynn. “We were able to show the landowners the plants and talk about the habitat that false mermaid-weed is relying on to persist at this site. It speaks to the importance of good stewardship of private lands in Vermont. If the riparian buffer along this stream hadn’t been kept intact, neither false mermaid-weed nor wild garlic would be here.”
The Vermont Fish and Wildlife Department plans to work with nearby landowners to survey riparian areas along the stream for additional plants. More occurrences of false mermaid-weed have now also been documented on protected lands just downstream of the rediscovery site.
“We think that there could be more unmapped populations of false mermaid-weed downstream on both private and public lands,” said Glynn. “Our planned inventory work will give us a better understanding of false mermaid-weed’s habitat needs and distribution. Ultimately, we want to know how we can help this species flourish in Vermont into the future.”
